On June 3rd Marlins pitcher Henderson Alvarez threw an 88-pitch shutout against the Rays scattering eight hits while not issuing a walk. On July 11th Marlins pitcher Henderson Alvarez also gave up eight hits while not issuing a walk but only made it five innings after surrendering 6 runs. While the circumstances surrounding these two starts aren’t completely the same they do a good job illustrating the phenomena of cluster luck.

Cluster luck, originally discovered and coined by Joe Peta in his book Trading Bases, essentially tells us how lucky teams have been by measuring the difference in the expected number of runs scored by a team based on its power (total bases), and base runners (hits/walks) and its actual number of runs scored. In Alvarez’s July start above he was a victim of poor sequencing, allowing his hits in bunches rather than spreading them out over the course of his start. For a more complete (and easier to understand) definition and some real world examples check out this and this.

What I will be attempting to do in this article is figure out a way to accurately estimate how many runs a pitcher should have allowed, and subsequently what his run average should look like, and then pinpoint certain pitchers who have been lucky or unlucky so far this season. Basically I am trying to normalize a pitcher’s RA by adjusting for sequencing and cluster luck.

Fortunately for me the heavy lifting for part one has already been done thanks to Dan Smyth. His metric, Base Runs (BsR), was developed and popularized in the early 1990’s and is an extraordinarily simple yet accurate way of estimating runs allowed using standard box score statistics. Base Runs for pitchers takes four inputs, innings pitched, hits, walks, and home runs, which are converted into four factors, A, B, C, and D. The final formula looks like A*B/(B+C)+D. For a lengthier piece on Base Runs, it’s properties, and it’s pros and cons consult this and this.

I took these statistics, including run average, for every pitcher in the majors through July 12th and figured his expected runs allowed by Base Runs, then converted it to Base Run Average or BsRA and took the difference between BsRA and his actual RA. I also calculated the pitchers’ RA- and BsRA- by taking the pitcher’s RA or BsRA and divided it by the league RA or BsRA (for reference the league RA is 4.14 and the league BsRA is 4.19). By taking the difference between the two, (BsRA-)-(RA-), we can figure out the percentage of extra runs compared to league average the pitcher should have allowed.

In the tables below you’ll see I’ve given this stat the name Luck%, a poor name admittedly since we’re dealing with percentages and I’m sure the differences aren’t completely due to luck but the name will have to do until I think of something better. For example Max Scherzer’s RA- is 80.92 (RA of 3.35/league RA of 4.14) meaning he has allowed runs at around 81% of the league average, but his BsRA- is 88.62 (BsRA of 3.71/league BsRA of 4.19) meaning he should have allowed runs at around 89% of the league average. We then get a Luck% of 88.62-80.92=7.71, so Scherzer should have allowed 7.71% more runs compared to league average, he has a Luck% of 7.71.

Whew. Now we can get to the names.

First the top ten qualified pitchers who have had their numbers most positively affected by cluster luck.

I like this list since it is very diverse. We have pitchers who have been pleasant surprises this season but who we all know aren’t really that good (Vargas and Simon). Older pitchers experiencing a late career resurgence (Beckett and Buehrle). Great pitchers (Greinke and Tanaka) and not so great pitchers (Chen). Hard throwing (Alvarez) and soft throwing (Young). High strikeout and low strikeout etc. etc. It’s good to see that not just one type of pitcher is affected giving me confidence that cluster luck does play a factor in a pitchers numbers to such a degree even this late in the season.

Now on to the top ten pitchers who have had their numbers most negatively affected by cluster luck.

This is a slightly less diverse list. Most of these guys are having disappointing seasons, but perhaps they haven’t been as bad as we think. Four of these guys have a below average RA, but an above average BsRA (or perfectly average in the case of Kuroda). Then there’s Anibal Sanchez who might just be one of the most underrated pitchers in baseball as his BsRA is seventh in all of baseball.

So what does Luck% end up telling us about a pitcher? We know that pitchers have little control over what happens after a ball is put in play, but what we’re doing here is figuring out which pitchers have been victimized by poor sequencing. Perhaps we can look at Luck% the same way we look at BABIP. If the measure is abnormally high compared to a pitcher’s career rate and the pitcher hasn’t made a substantial improvement in his mechanics or pitch repertoire perhaps some regression is in order.

So is Anibal Sanchez due for a spectacular second half? Maybe not. A myriad of factors could be influencing his low Luck%. We know that in general offense goes up when runners are on base and Sanchez could be especially susceptible to allowing runs to score in bunches. He has a slow move to the plate potentially allowing more runners to steal and get in scoring position. Perhaps his stuff is less effective from the stretch due to a breakdown in mechanics. Maybe he focuses too much attention the runners on base and not enough on the one at the plate, I really don’t know.

I only have half a season of data on 100 or so pitchers so obviously more research is needed. One could find the correlation between Luck% and peripheral stats such as K% and BB%, or find year to year correlations for Luck% to find out how much variation is actually luck and how much is skill. I’d definitely be intrigued by those results and I’ll likely revisit these numbers when the season ends.

I’m still relatively new to performing this kind of analysis so any constructive criticism would be greatly appreciated or if you’ve seen something like this done elsewhere on the internet. If you have suggestions for any improvements (especially the name) or further research I’d love to here it. If you think I majorly screwed up somehow I’d love to hear about too.

Max Scherzer has gotten off to a great start in his defense of the 2013 Cy Young Award, but after rejecting a likely substantial contract extension a month ago every time he walks out to the hill is perhaps one less time fans have to see him pitch in a Tigers uniform. It seems more and more likely with each passing day that Mike Illitch, Dave Dombrowski and Co. will not extend Scherzer and will instead let  him test free agency.

After inking Miguel Cabrera to an eight-year extension worth $240 million through 2023 earlier this month, it would seem foolish for the Tigers ownership to try and squeeze another enormous contract onto the roster. If Scherzer were to hit free agency we could expect his contract to fall somewhere around Cole Hamels’ $144 million or Zack Greinke’s $147 million deal, somewhere around $24 million/year. Scherzer could get more, depending on the strength of other free-agent pitchers, amount of years a team wants to give him, and how much Scott Boras whines. That would mean Detroit is committing close to $75 million for three players, a burden for any team. Could there be an alternative, from the Tigers’ perspective, to signing another pitcher about to hit his 30’s to a $24+ million deal?

We know the Detroit organization has been in win-now-at-all-costs mode for years, but they just finished an off-season in which they made a very real effort to get younger and more flexible. We’ve seen a number of teams, the Braves and Rays among them, extend their young players to relatively team friendly deals a few years before they hit free agency. It just so happens that the Tigers have two perfect extension candidates on their roster.

Austin Jackson is perhaps one of the more underrated players in the Major Leagues. He’s been an above average center fielder by both DRS and UZR, an above-average base runner, has slashed .279/.345/.420 in his career good for a .336 wOBA, and been worth 15.0 WAR in just over four seasons with Detroit. He’s in his age-27 season and by all looks is just entering his prime years. Currently, Jackson is playing on a $6 million dollar deal and is due to hit free agency in 2016. If Detroit’s ownership believes he’ll continue to improve his plate discipline — Jackson struck out in 21% of his plate appearances last year although his .77 BB/K ratio is a significant improvement over the .28 mark he put up in his rookie year — and his power (.140 career ISO), then they should seriously think about locking him up sooner rather than later. If new manager Brad Ausmus continues to be more aggressive on the base paths with this team than his predecessor, Jackson could have the 20/20 season a lot of fans were hoping for, which would send his price through the roof if he’s left to test free agency.

When you remember Rick Porcello was a first-round pick in 2007 and the hype around him was such that he was expected to be Justin Verlander 2.0 in the Tigers rotation it’s hard not to be a little disappointed with the outcome of his career so far. When you also remember that he only pitched 125 innings in the low minors, came up at age 20, and has seen his ERA and FIP improve yearly as well as a surge in his strikeout rate and a decline in his walk rate it’s easy to see how he could eventually reach his mid-rotation ceiling. Porcello is still only 25 years old, playing on an $8.5 million deal and, like Jackson, is a free agent after the 2015 season.

An extension for Porcello would give the Tigers a rotation of Justin Verlander, Anibal Sanchez, Porcello, and Drew Smyly for at least three years after 2014. Jackson contributes a middle of the order bat along with premium defense in center field. If Scherzer were to sign with another team, the Tigers could extend both players for at most a few million over what Scherzer would make per year and that would be made up by the $14 million coming off the books from the Torii Hunter contract who is unlikely to re-sign. Instead of committing $75 million to three players, Detroit can commit that to two superstars, two above-average players with the potential to put up some star seasons in their prime, and perhaps another outfielder to cover for Hunter. If the Tigers are really committed to roster and payroll flexibility they will let the reigning Cy Young winner walk and lock up two young talented players entering the prime years of their career.