WAR is considered by many members of the baseball community to be the best all around evaluator of a player’s value to his team.  It is used to evaluate player’s of different positions and from different eras.  However this might not be as useful in looking at players from different position.

I have developed a model that shows that one win at each position is not actually created equal.  This season Buster Posey and Ben Zobrist have a similar WAR — 5 and 4.9 respectively — but I don’t think anyone will argue that Posey is the better player. In order to determine how much more valuable Posey actually is I created a regression equation.  In order to develop this equation I took stats from the past 5 full seasons (2009-2013).  I took each team’s total number of wins and found the average win total over those 5 seasons.  Then I used the FanGraphs section that allowed me to look at each team’s total WAR by position.  For each position I took the total WAR and divided it by number of games “played” at that position and then multiplied it by 162 to find a season equivalent for each team at each position.  For starters and relievers I just took the WAR numbers and divided by 5.  Then I took these numbers for each team and regressed it against average wins.

Note: I did not include DH as the stats that come from the DH are included in other positions (ex: If Joe Mauer DHs then his stats are included in the catcher WAR).

The resulting equation is as follows:

Wins= 49.3870 + 3.3251 * C + 0.9527 * 1b + 1.5122 * 2b + 1.4703 * SS + 1.5447 * 3b + 1.0027 * Rf + 1.4031 * Cf + 0.4450 * LF + 0.7521 * SP + 0.5137 * RP

R: 0.95

R-squared:0.91

A few quick observations of the equation make sense. An additional win at the catcher position is worth much more than any other position because teams value catchers who can both hit and play solid defense but are extremely willing to sacrifice offense if the guy can play defense. Additionally it supports the theory that the best teams are strong up the middle with SS, 2B, and CF being more valuable than corner OF spots and 1B.

While it is regressed against wins I don’t feel the best application of this model is to predict a team’s wins.  The best application of this will be to evaluate the players to sign in free agency.  This past offseason the Yankees did not sign Robinson Cano to a large contact and instead signed players like Jacoby Ellsbury, Brian McCann, Kelly Johnson, and Brian Roberts.  Johnson and Roberts were supposed to split time at second and Ellsbury and McCann were supposed to be upgrades and C and CF over what the Yankees had had.

Looking at this chart this shows the WAR by position extrapolated for 162 for the three positions where the Yankees made major changes this offseason. Using the model the moves the Yankees made have actually led to a decrease of over one win.  While that may not seem like a very large difference the Yankees are in the middle of the wild card chase and could fall around one game out the playoffs.  Additionally, the lack of Cano and the struggles of Johnson and Roberts forced the Yankees to go out and trade for Martin Prado and Stephen Drew.  Without the contributions from Prado the Yankees second base position would actually have a WAR of below 1 which would have created an even bigger difference caused by not re-signing Cano.

This model is extremely useful for teams with limited budgets as it could help them determine what players and what positions they should sign in order to maximize their win totals.

So far this season Jake Arrieta has looked like an ace, pitching to a 2.53 ERA which is over 2 points better than his career average.  His K/9 is at a career high and his BB/9 are at a career low — 9.19 and 2.32 respectively.  However, the biggest difference in Arrieta’s success comes from his ability to limit home runs this season.  His .36 HR/9 is significantly lower than his career average of 1.01.  People have been questioning whether or not Arrieta can sustain this or not and how he has become a completely different pitcher this season.

The key to this change in Arrieta could conceivably be coming from his change in pitch mix this season.

The major thing that stands out from looking at his pitch F/X data is that Arrieta has begun to use his slider more than ever before in his career this season.  Almost twice as much as his previous career high.  Arrieta has actually been using his slider as his most frequently used pitch.  The heavy increase in Arrieta’s usage of his slider has been at the expense of both his sinker and his four seam fastball which are both at or near career lows this season.  What is interesting is that Arrieta decreasing his usage of a sinker has actually lead to a career high in GB%.

This lead to an interesting idea of what other starters this season have been using a breaking pitch as their most-used pitch this season.  That found seven such starters including Arrieta.  Here is their pitch mixes according to pitch F/X.

What is interesting about this group is that most of these guys other than Arrieta have all featured their breaking stuff as either their number one or two pitch for much of their careers while Arrieta just began featuring it this season.  Although Tyson Ross did use the slider a lot early in his career, his usage of the pitch has significantly increased over the past two years — 25.5% in 2012 and 32.2% last season.  He has had a similar change in success to what Arrieta has seen this season.  Ross’s GB% is at a career high beating his previous career high that he set in 2013 by 3 percentage points.  His K/9 and BB/9 have also risen and dropped respectively over the past two seasons once he began to use the slider more and more.

Using Ross’s pitch usage changes as a blueprint for Arrieta’s potential future successes the trends seem to fit.  The only place Arrieta truly changed that Ross did not see a change is in his HR/9.  Arrieta was homer prone early in his career while Ross never was.  However, Ross’s pre-change groundball rate was higher than Arrieta’s which supports his ability to keep the ball in the yard.  Thus is it not insane to think that Arrieta could keep up the success he has had this season as long as he continues to feature his slider like he has this season.

I recently set out on a quest to determine the best way to evaluate relief pitchers in order to find the most valuable relievers this season. That led down a number of different paths of research that all centered around two main ideas. The key to success in relief pitchers is their ability to pitch out of jams and to pitch in big situation, which in a sense go hand in hand. Since the introduction of the save as a stat teams have began using their best reliever only in the ninth inning when they have a lead of 3 runs or less.   However, this is not always the most important part of the game and often times the most important innings are the 7^th and 8^th.

So in order to truly determine the best reliever a good place to start is looking at the importance of the innings that each pitcher has thrown. This is where leverage index comes in. The higher the LI the more important the inning. This is a combination of score, situation, and place in the order.

The other key to relievers’ success is their ability to work out of jams. Often times a relief pitcher is brought in to the game with runners in scoring position. This is why ERA is not a good indicator of the success a reliever because it does not factor in the inherited runners that scored on that reliever. This is where RE24 can be of extreme help. RE24 is a counting statistic that uses a run expectancy table to show how many runs better than average a pitcher is based solely on game situation. This means than a pitcher will be penalized for allowing an inherited runner to score. However, since this is a counting statistic by dividing it by innings pitched it can be turned into a rate statistic, which allows more equal comparison between pitchers.

Since RE24 does not factor in the importance of the situation in the context of the game combining it with LI is a good determination of the value of the individual relievers. So in an attempt to determine this year’s best reliever I used this simple formula:

Reliever Rating (RR)=(RE24/IP)*LI

According to this stat the better the pitcher the higher the number and the worse the lower the number. A rating close to 0 indicates an average pitcher as a RE24 of 0 means the pitcher performed exactly as expected in the given situations. The worst ratings are the negative numbers meaning that pitcher was below average.

Here are the top 10 relievers according to RR thus far in 2014.

This list includes several big-name closers and several setup men. Looking at the value of these pitchers using this formula shows how not all inning pitched are equal. This is not a valuation of the true talent of the pitchers but what it does is create an even way of looking at the importance of each pitcher to their team. Not surprisingly, there are several closers among the leaders as due to the late game innings they pitch and the fact that they typically pitch in close games their leverage indexes are high. Yet for pitchers like Darren O’Day his high ranking is due to his very high RE24 total. This is due to O’Day’s ability to strand runners so far this season (96% LOB%). For a comparison, since 2000, the best single season total belongs to Jonathon Papelbon in 2006 with a RR of .95.

This can also be used to look at the worst relievers thus far this season.

Many of these names are not surprising as players like Nathan, Frieri, and Johnson failed miserably in their different stints as closers thus far this season. Many of these pitchers have very low RE24’s which supports their low ranking but pitchers like Steve Cishek (15^th worst) who have been slightly below average (-3.18 RE24) are punished for struggling in high-leverage situations (2.11 LI).

When Spring Training rolled around the Yankees had one the better rotations in baseball on paper. CC Sabathia lost weight, Huroki Kuroda was back for another season, Ivan Nova was poised for a breakout and they had two new big additions to the staff. Masahiro Tanaka was fresh off setting records in Japan and signing a massive contract and Michael Pineda was healthy and finally ready to contribute. However, at this point in the season Kuroda is the only one who remains from that highly touted staff. Nova and Sabathia have suffered season ending injuries with Tanaka out since the All-Star break and his rest of season and possibly even 2015 season in question. Pineda is currently on a rehab stint and could rejoin the rotation as soon as Wednesday after missing most of the season to this point with a multitude of injuries.

However, despite all of these injuries Brian Cashman has made a few minor moves and some strategic callups to help build what has become a very successful rotation. Kuroda has still remained part of the rotation with Cashman adding Brandon McCarthy and Chris Capuano and calling up pitchers like Shane Greene and Chase Whitley. David Phelps had also joined the rotation replacing the injured starters yet he himself has also gotten injured and found himself on the disabled list. They also added Esmil Rodgers who in a spot start on Friday pitched well earning himself a win and potentially another start until Pineda returns.

The question remains though although this rotation has been extremely successful to this point can they maintain the success enough to carry the Bronx Bombers to the playoffs? The Yankees currently sit six games out of first in the division while also trailing in the race for the second wild card spot by 1.5 games need to the rotation to pitch well in order to make a run at October.

As of right now the four guys poised to remain in the rotation for the foreseeable future are Kuroda, McCarthy, Capuano, and Greene with the fifth spot likely being Pineda’s when he returns, likely in the next two weeks.

Kuroda has pitched much like the Yankees had expected of him throwing to a 3.97 ERA, which is slightly above his 3.46 career ERA, but it is an anticipated regression for a pitcher in his age 39 season. For his career Kuroda although he has thrown less innings had been a better second half pitcher (3.52 ERA vs 3.39) and this season the trend has continued with Kuroda throwing to a 4.10 ERA in the first half and he has a 3.42 ERA so far in the second half. The Yankees have tried to limit the aging Kuroda’s pitch count and innings so far this season wanted to ensure the right hander was stronger down the stretch run as Kuroda faded in 2013 late in the season. If Kuroda figures to maintain his career splits and pitch better in the second half he should be able to maintain his success to this point in the season and be the pitcher he was expected to be early on in the season.

The two minor trades that Cashman made before the trade deadline are also going to factor into the Yankees postseason chances. Thus far McCarthy and Capuano have been huge for the Yankees pitching to a 2.21 and 2.84 ERA respectably over 9 starts combined and have a combined 5-1 record in those 9 starts. So far over his 36 innings as a Yankee McCarthy is pitching much better than his career averages in K/9, BB/9, and HR/9. He has faced 155 batters as a Yankee meaning only his K rate has stabilized (70 BF). Thus the other two statistics especially his HR rate which is currently at .74 is much improved compared to his career 1.03. The improved HR rate is likely what has caused his vast success to this point, and pitching down the stretch in the power-hitting AL East and in Yankee Stadium, chances are this will regress back to his career averages and McCarthy will once again be a back-of-the-rotation starter, as opposed to the ace he has been for the Yankees so far since the trade.

Although Capuano’s sample size has been smaller than McCarthy’s his success has been similar. According to career averages Capuano is striking out around a half batter more per nine and walking about a half batter less. Those don’t account for the increase in success he’s had. So far in 19 innings in New York Capuano has yet to allow a home run. However, looking back at his time earlier this season with the Red Sox his season HR/9 is at .53 significantly lower than his career 1.20. Unless at the age of 35 and in his 10^th season Capuano has magically figured out the secret to keeping the ball in the ballpark he will likely regress back and beginning pitching more like he has in the past with his ERA moving back into the range of his xFIP which currently sits at 3.35 as a Yankee and 4.07 for his career.

Lastly, that leaves the rookie revelation that has been Shane Greene. As Eno Sarris points out, looking at Greene’s pitch mix gives him a few good comps of successful major-league starting pitchers. However, Greene’s minor league track record did not signal anything similar to this type of success he’s had since being called up. However, there is room for excitement as Greene has posted the lowest K/9 rate since his call up than he did at any point in his minor league career meaning that rate could see an increase. Also, his walk rate seems to be on par with his minor-league record, especially when looking at his numbers over 2013 and the first half of 2014.

Where Greene has succeeded in the big leagues has been with his ability to limit BABIP (.268) and his low HR/9 numbers. Throughout his minor-league career the highest HR/9 Greene posted at any stop was in rookie ball when he posted a .79 rate over 23 innings. Thus far in 37 big league innings Green’s HR/9 has been .72. He has a track record of being very successful at keeping the ball in the ballpark. However, what remains to be seen is if his BABIP comes back down to Earth and his K rate remains low. If he doesn’t retain the ability to strike batters out like he did in the minors and regresses to his minor-league BABIP numbers — only one stop lower than .330 — Greene figures to regress to the below-average pitcher he was in the minors

Over the last month the Yankees’ makeshift rotation has been keeping them alive in the playoff race. However, looking at each member of their rotation, there is reason believe that significant regression is coming with Kuroda being the only one performing near his career averages. Unless each of these arms continues this unprecedented success or Pineda and potentially although unlikely Tanaka return and pick up right where they left off it doesn’t seem like this current Yankee rotation has what it takes to reach the playoffs.

ISO is used to determine a hitter’s ability to get extra-base hits as it is a measure of slugging percentage minus batting average.  So using the same idea and with the help of slugging percentage and batting average against we can evaluate the best pitchers at limiting extra-base hits.  First we will look a the 10 best starting pitchers in 2014 according to ISO.

As would’ve been expected the top ten includes some of the best pitchers in the league.  Guys like Wainwright, Kershaw and many of the others are also found near the top of the ERA leader-boards.  However, one name more than the others does not quite fit with the others on this list, Jarred Cosart.  The hard throwing right-hander who was traded at the deadline from Houston to Miami has been one of the best pitchers in the league at limiting extra-base hits.  However, his ERA — 4.51 — does not match.

Cosart’s lack of success despite his ability to limit hitters to singles is due to two areas where he struggles.  The first is stranding runners.  Cosart’s LOB% of 67.4 is 9th worst in the league.  Although Cosart has excelled in mainly allowing singles he has not done a good job of keeping those hits from coming around to score.  However, the main area that Cosart has struggled this season is his control.  His BB% is tied with A.J. Burnett for third worst in the league at 10%.  Thus Cosart’s high frequency of baserunners due to his walk rate and his struggles in stranding runners have caused the hits he has allowed to do more damage.

Again not surprisingly, several of these pitchers are among the worst qualifying starters in terms of ERA in 2014.  With the bottom 4 pitchers all with high-4 ERAs and Jackson pitching to a 5.66 ERA.  However, there are also a few outliers in terms of success with Beckett and Chris Young both pitching to much better ERAs than their ISO allowed would suggest.  Beckett’s 2.88 ERA is good for 19th best in the league with Young’s ERA placing him in the top 40 among starters.

Where both pitchers have succeeded this season is in stranding runners.  Beckett ranks number 1 in the league in LOB% while Young finds himself at 4th.  Both pitchers have been very successful at pitching themselves out of jams this season.  For that reason both pitchers have been able to allow a large amount of extra-base hits and still be among the best in the league at preventing runs.

Platoon splits have become a major part of baseball today.  The Athletics have ridden a split of Jaso and Norris to production from their catcher position.  Many left-handed starters have had success against righties and many have struggled.  Over the course of his career Cole Hamels has had more success against RHB than LHB (.294 vs .301 wOBA).  Hamels is known for his best pitch — his change up — which has helped him neutralize RHB throughout his career.

So often when a LHP struggles against RHBs the common fix is to use a change up more often or to improve the change up.  However, for some pitchers this model does not work.  Dallas Keuchel, a pitcher who used a change up as his primary offspeed pitch against RHBs in the beginning of his career struggled still against righties.  As shown in this article, from the time his career began until May 31st of this season Keuchel was one of the worst starting pitchers against RHB.  However, by breaking this down season by season it can be seen that Keuchel’s numbers have actually improved as his career’s progressed.

The key to Keuchel’s increased success against opposite-handed hitters seems to be found in his pitch selection.

Keuchel has been an often-discussed topic on this site this season.  The key to his success this season has been his increased use of his rapidly-improving slider which was covered by Eno Sarris here. As Sarris states the slider will allow Keuchel to have increased success against lefties.  However, looking at Keuchel’s splits this season shows he has improved his numbers against righties significantly. According to PitchF/x data Keuchel has used the slider significantly more against righties this season.  He has done this at the expense of four-seam fastballs opting to throw more two-seamers and sliders.

While he is still using the changeup at around his career averages, his heavy increase of sliders in the biggest difference in his way of attacking hitters.  As his numbers for the season have shown he is limiting home runs and striking out the highest percentage of right-handed hitters in his career.  This has also lead to a significant improvement in his wOBA allowed. This season against righties the slider has produced a better than MLB average whiff rate (18% vs 13.%).

Keuchel provides an blueprint for other left-handed starters who struggle against righties.  Contrary to typical belief that in order to improve against opposite-handed batters pitchers must develop their change up, Keuchel has begun using his best offspeed pitch — the slider — more as a putaway pitch against off-handed batters.  Keuchel has become the poster boy for pitching to strengths, riding his sinking two-seam and slider to a breakout season while significantly improving his platoon splits.

Another pitcher who was mentioned as the worst in the league against righties was Eric Stults.  Stults, a lefty like Keuchel, features both a slider and a change up.  Additionally, much like Keuchel, Stults’s best offspeed pitch according to pitch values is his slider.  However, looking at his pitch selection to RHB he has used the change more than twice as much as the slider since 2007 (25.6% vs 10.8%).  If Stults followed in the footsteps of Keuchel and began to use his best pitch more against opposite-handed hitters it could cause him to minimize his platoon split and make him a better all-around starting pitcher.

Earlier this month the Yankees took a chance on Brandon McCarthy, trading Vidal Nuno to the Diamondbacks for the sinker-balling right hander.  While McCarthy’s numbers in Arizona were ugly (5.01 ERA), his FIP was much better (3.82).  Through 4 starts the investment the Yankees made has paid off.  McCarthy has pitched to a 3-0 record with a 2.55 ERA.   Since the trade many of McCarthy’s peripherals have not changed much however, there have been a few differences.

Two keys factors for pitcher success — K% and BB% — have not changed much with K% decreasing slightly and BB% increasing sightly, although neither can be looked at as the reason McCarthy has been so much better since the deal.  Another important stat to look at is his BABIP, which, has improved a few percentage points since the beginning of the season but is still above his career average of .297.  However, a major difference that can be seen in McCarthy’s numbers since the trade is his GB%.  In recent seasons as McCarthy has began featuring his sinker more his groundball percentage has increased significantly.  the 55.3% he showed with the Diamondbacks was more than 7 percentage points higher than the career high he set in 2013.  Seeing this major change in GB% opens the question of what exactly McCarthy has been doing differently with the Yankees.

During a few of McCarthy’s starts with the Yankees, New York broadcaster Michael Kay has mentioned that McCarthy did not throw his cutter as frequently with the Diamondbacks compared to how often he has used it since the trade.  Looking at his PitchF/x pitch selection data does show an increase in the use of his cutter but it also shows several other interesting trends.

As Kay has noted McCarthy has used his cutter more frequently but the increase is minimal compared to several other big changes McCarthy has made.  With the Dbacks McCarthy used his curveball more that a quarter of his pitches making it his second most frequently used pitch.  However, once he was traded McCarthy had been using the cutter as his second most common pitch.  However, the significant drop in his curveball usage did not get added to his cutter usage it instead was added to a pitch he did not use in Arizona, a four seam fastball.

Since his trade to New York from Arizona Brandon McCarthy has been a completely different pitcher.  While his ability has not changed and the park has not been much of an improvement (103 for NY 104 for ARI) the biggest difference in McCarthy as a pitcher has been in his pitch selection, once again featuring a four seam fastball while reducing the usage of his curveball.  To this point the move to the Yankees may have been exactly what McCarthy’s career needed simply because it allowed him to change the way he attacks hitters.