(Note: “Patience” here is really shorthand for “ability to get on base,” whether that’s via hits or walks. But it’s pithier and generally gets the point across as to what I’m trying to look at.)

In one of the Thursday chats on FanGraphs with Eno Sarris, I posed the following question, which he posted and the chatters answered collaboratively: Name the three players (minimum 3000 plate appearances) in the expansion era (since 1961) with a career on-base percentage above .400 and an isolated power number below .200. (Answers at the end of this post.)

In the entirety of baseball history, 36 players with 3000 plate appearances have achieved such numbers, and 24 since the beginning of the 20th century, but there are only three such players in the past 50 years. This is not particularly surprising; you won’t see many career lines such as Ty Cobb’s .366/.433/.512 anymore, or even Paul Waner’s .333/.404/.473.

But just how has the relationship between hitting for power and getting on base changed through the years?

Since we started at the individual level, let’s continue there. Let’s start with the last 20 years, from 1994-2013. Excluding pitchers, the league-wide on-base percentage was .338 and the league-wide ISO was .159. Over that time period, 761 players have had 1500+ plate appearances. How they break down on OBP and ISO lines:

Now, 1901-1920, during which time only 377 players had 1500+ plate appearances and the league averages were a .326 OBP and .082 ISO:

In either era, a substantial majority of players had either both an above average OBP and ISO, or both were below average. However, that majority is 59% in the last 20 years and was 68% in the deadball era. So one conclusion we can draw is that fewer players now sacrifice power to reach base or vice versa than they did in the olden days. (Whether they did so consciously or not.)

However, this breaks down if we go to extremes.*

From 1994-2013, 13 players had an OBP 10% above average and ISO 10% below average, while there were 15 players with an ISO 10% above average and OBP 10% below average. Overall, 3.7% of all players with 1500 PA are here.

From 1901-1920, 8 players had an OBP 10% above average and ISO 10% below average and 5 players had an ISO 10% above average and OBP 10% below average. Overall, 3.4% of the players with 1500 PA.

Players who get on base without power or hit for power without getting on base are basically as common now as they were in the dead ball era. But it’s also less common now for a player to sacrifice one or the other to any degree.

What about this power-patience relationship league-wide?

First, below are some league-wide stats over various time frames (excluding pitchers):

Time Frame	OBP	ISO	BB%	HR%
1901-present	.333	.130	8.7%	2.0%
1901-1920	.326	.082	7.6%	0.4%
1994-present	.338	.159	8.8%	2.8%
1901-1960	.341	.111	8.5%	1.2%
1961-present	.332	.142	8.8%	2.4%

The comparison between 1901-1920 and 1994-2013 really isn’t surprising. Most fans know that the dead ball era was not a time to hit for power, while the most recent times have generally been more offense-happy, especially the late 90s/early 00s.

In that chart we also see all of post-1900 baseball divided into two eras, divided along the Baseball Reference-identified beginning of the expansion era. OBP was actually higher before the Sixties while power was lower.

For now, I want to conclude with the year-by-year ratio of extra bases (2B+2*3B+3*HR) to bases reached (H+BB+HBP), graphically. I realize this might have some flaws similar to those of OPS, but a simple ISO/OBP ratio be even worse in that regard. I wanted to strip out total plate appearances or at-bats, and just look at the average number of extra bases that were earned each time a player reached base, which the selected method essentially does. The difference between ISO/OBP and the ratio selected is, on average, about 4%. At any rate this should do for a quick comparison:

A lot of famous seasons like 1930, 1968, and 1987 are identifiable on the chart. (The lowest ratio of the expansion era actually occurred in 1976, not 1968, however.) Also, it wouldn’t greatly surprise me if Babe Ruth is single-handedly responsible for the sharp increase from 1918 to 1921. (He got on base a lot, of course, but his power was the thing.) Most importantly, however, it’s clear that over time the ability of Major League player to hit for power has gone up relative to their ability to get on base. This too is not surprising to those familiar with baseball history.

And so all of this really only gives us a limited idea of the relationship between reaching base and hitting for power over time. Over the next few weeks, we’ll go further into things, both on the individual level and league level. Working backwards, next week will focus on the data underlying the above line chart.

Answers to the initial question:

Joe Mauer (.405 OBP, .145 ISO)
Rickey Henderson (.401 OBP, .140 ISO)
Wade Boggs (.415 OBP, .115 ISO)

*It’s not a Rickroll, it’s a Joelroll, which is even better because it rhymes.

Happy 21st birthday, Bryce Harper!

In two seasons to date, Harper has posted a 128 wRC+ while hitting .272/.353/.481 in 1094 plate appearances.

Steamer projections have Harper projected to hit .266/.347/.464 as a 21-year old, which would make for a 125 wRC+. But if Harper posts a lower batting average, OBP, and slugging than he did in either of his first two years, I imagine that would be a major disappointment, not just for fans of the Washington Nationals, but for fans of the sport of baseball. And also, perhaps mostly, for the player himself. (But at least the projections have him down for a career-high 23 home runs.)

Changing gears for a moment, how about that Mike Trout. You may have heard, but some people thought he was the American League’s most valuable player after he hit .326/.399/.564 in 639 plate appearances in 2012. Then he somehow got even better as a hitter in 2013, posting a .323/.432/.557 line in 716 PA.

But when Trout was 19, he hit .220/.281/.390 in a 40-game, 135-PA cameo in 2011. Harper would crush that line as a 19-year old rookie in 2012. Then, of course, Trout’s age-20 season set an impossible standard that Harper had about a 3.4×10^9 percent chance of surpassing, if we’re being optimistic.

Because of the one-year age difference, had Trout just ended up reasonably good rather than ridiculously great, he might have served as a decent guide for how Harper could develop. Sort of a one-year advance copy. But Trout’s 2013 season confirmed that he is ridiculously great, so that idea is out the window for now.

What about other players who got their starts as teenagers? According to the Baseball-Reference.com similarity scores, Harper through his age 20 season has posted numbers most similar to Tony Conigliaro (956), Ken Griffey (954) and Mickey Mantle (954). All three of these players debuted in their age 19 seasons.

Mantle was already a great hitter when he was 20, posting a .311/.394/.530 line in 626 PA (158 wRC+), but the other two players set more worldly, but still great-for-20, lines: Griffey a .300/.366/.481 (666 PA, 132 wRC+) and Conigliaro a .269/.338/.512 (586 PA, 131 wRC+).

Harper’s wRC+ in 2013 was 137, slightly better than either Griffey or Conigliaro, but he only put in 497 plate appearances. Still, the three players had awfully similar age-20 seasons.

When he turned 21, Conigliaro’s effectiveness decreased to a 123 wRC+ and .265/.330/.487, before a recovery when he turned 22 (144 wRC+, .287/.341/.519, 389 PA) prior to the disaster that occurred on August 18, 1967, when he was hit in the face by a pitch.

Griffey’s improvement was steadier, as he posted a .327/.399/.527 line when he was 21 and a .308/.361/.535 one at 22 years old, with wRC+ marks of 148 and 145, before experiencing his first two 160 wRC+ seasons the next two years.

One more player I want to talk about in this context is Giancarlo Stanton. He fiddled around in A+ and AA when he was 19, because the universe doesn’t just up and grant every great talent the ability to hit Major League pitching as a teenager. Stanton instead debuted in his age 20 season and hit .259/.326/.507 (118 wRC+ in 396 PA) before hitting 34 home runs in his age 21 season with a 141 wRC+ and a .262/.356/.537 line in 601 PA.

So where the heck are we now? I just shared a lot of names and players and numbers and slashes, but none belong to Bryce Harper. He’ll have a heck of a lot more to do with his development than Mickey Mantle’s ghost.

I think the record shows, however, that players who hit well when they are 19 and 20 generally don’t stagnate at 21. The projected line from the beginning of this post still seems low.

To conclude, here is a possible range of outcomes for Bryce Harper in 2014:

Worst-case: His health remains an issue. His stats end up about as projected…or worse.

Mid-case #1: He actually gets healthy but still faces a Conigliaro-like decline between his age 20 and age 21 seasons. (Although, Conigliaro’s decline still left him hitting at a darned good level.)

The Steamer projection is somewhere between this and the prior case.

Mid-case #2: Ken Griffey. Don’t let the version of Ken Griffey from his mid-20s in the mid-90s, the version who hit 56 home runs in consecutive seasons, interfere with the classification of this as a “mid-case.” A 10-20 point jump in Harper’s wRC+, as Griffey experienced when he turned 21, would be a welcome development and continue Harper on his perennial all-star path.

Best-case: Mike Trout. I might have skipped a couple mid-cases, but let’s get back to Trout. It’s going to always get back to Trout, I think, for years when we have conversations like this. But if Trout could struggle when he was 19–unlike Harper, Mantle, Conigliaro, Griffey (sorry Stanton)–and then explode when he turned 20, why can’t the other once-in-a-generation talent of this generation experience a similar jump? (Please allow me a “why can’t” when talking about best-case scenarios.) It wouldn’t be a change from bad to great, but good to unfathomable, and it would come a year later, but maybe instead of having Griffey’s age-20 season and Griffey’s age-21 season, Harper can skip right to Trout or Mantle’s age-21 season.

The “Griffey-Griffey” path is still a more realistic hope for those looking for Harper to exceed the computed expectations set by Steamer. I don’t think a 150 wRC+ is out of reach, but even a 140 or 145 wRC+ or so would be a nice continuation for Harper’s career.