It was my first sabermetric argument. At least, the first one I remember. The year was 1984, and my beloved Mets were battling the Cubs for the NL East division lead. I had a buddy who felt that the Cubs were going to take it, because the Mets had too many young players on their roster (guys named Strawberry and Gooden) who wouldn’t be able to handle the pressure of a pennant race. I took exception, wondering why younger players can’t play well in pressure situations. Back and forth we went.
Well, the Mets lost four straight August games to Chicago, never really recovered, and the Cubbies eventually won the division by six games. Strawberry had a lousy August (.177/.333/.241), though he bounced back in September (.652 slugging), and Gooden was awesome in September (1.29 ERA). On the surface, my friend seemed be right, but I never did cede the point. I’ve been told I’m stubborn.
Five years later, the Cubs won the division with a number of young guys named Maddux, Grace, Dwight Smith and Mitch Williams. I thought of pointing that out to my friend, but I’m not one to dwell on things. Just because I still remember the argument nearly 25 years later? Nah, not me.
So this year we have the youthful Tampa Bay (not Devil) Rays battling the middle-aged Boston Red Sox for the AL East division lead, and it’s back to the same subject. I haven’t stayed in close touch with my old buddy (wonder why?), but there are still plenty of fans and writers who believe that veteran players handle pressure better than young players, as in…
Having the ability to win is not the same as having the ability to actually succeed in the big leagues.
The apparent upshot is that experience is critical when pennant pressure rears its ugly head, and veterans know how to win in those situations. Young players know only how to play well.
You know, I still don’t get it. I certainly appreciate that there are players who may not handle pennant pressure as well as others. But why are we so sure that it’s primarily a function of experience? Haven’t most major-league rookies already been exposed to intense crucibles of competition?
Some people like to point to Jose Reyes’ struggles last September as a key reason for the Mets’ flop, but they ignore 41-year-old Tom Glavine’s 6.10 ERA the same month. Yes, Rick Ankiel developed Steve Blass disease at a young age in postseason play, but Steve Blass developed Steve Blass disease at the age of 30, after eight years in the show. So where’s the evidence?
I once read that the difference between a story-teller and a statistician is that a story-teller wants you to suspend your disbelief (you’re just not going to enjoy West Side Story unless you’re willing to believe that Puerto Rican gangs like to sing and dance), but a statistician wants you to suspend your belief (clutch hitting may “exist,” but if you can’t find it in the stats, so what?).
I love a good story (even ones with singing gangs), but I’m a baseball belief suspender. Pennant pressure and experience make for a good story, but are they really factors? Let’s see if we can figure it out.
For the following analysis, I’m going to rely on Win Probability Added. WPA is perhaps the most appropriate stat for investigating these questions, because it measures the impact of every play on a team’s chances of winning the game. None of this “production” vs. “winning” distinction. In WPA, we measure production in terms of its impact on winning the game.
Thanks to David Appelman of Fangraphs, I compiled every play from 2006 and 2007 along with its impact on the team’s win probability of each game. I broke down each play according to the age of the batter (using June 30 to set the birthday) and included only teams that were involved in their division pennant race. Finally, I broke the WPA stats into two time categories: before and after August 1.
In other words, I’ve got a two-year WPA list for batters involved in pennant races, broken out by age and time period (before and during the pressure-filled months). After staring at the data for a while, I picked out a pattern and grouped the batters into four groups. Here’s how the data lays out (explanation to follow):
Before August 1 Ages Win Adv. Loss Adv WPA WPA% 21-24 494.7 -497.4 -2.7 0.499 25-30 1344.0 -1325.9 18.1 0.503 31-35 938.1 -937.6 0.4 0.500 36-40 219.6 -211.5 8.1 0.509 After August 1 Ages Win Adv. Loss Adv WPA WPA% 21-24 272.0 -262.9 9.0 0.508 25-30 663.4 -676.5 -13.1 0.495 31-35 460.6 -445.6 15.0 0.508 36-40 103.9 -104.3 -0.5 0.499 Ages WPA Diff 21-24 11.8 25-30 -31.2 31-35 14.6 36-40 -8.6
Let’s start at the end of the table. “WPA Diff” is the difference in each age group’s WPA from the first period to the second. As you can see, the youngest age group actually improved their win contributions in pennant pressure games. The 25-30-year-olds were the ones who “wilted under pressure.” Ages 31-35 improved, and the 36-40 group declined somewhat.
I also broke out the data in the first two parts of the table, for those who want to see it. I listed the number of Win Advances (Win Adv.) and Loss Advances (Loss Adv.)* for each age group, as well as their WPA and WPA% (which is basically a WPA rate stat equal to win advances over absolute total advances). This is important information, because not every age group played the same amount of time (which is what win advances and loss advances basically represent).
*Win Advances are positive WPA contributions and Loss Advances are negative WPA contributions.
So, if you use WPA% as a rate stat, you see that the changes from before and after August 1 were roughly equal: The youngest age group improved .009 points in WPA% (from .499 to .508) in pennant races; the next age group declined .008; the next group increased .008; and the oldest group declined .010 points.
By the way, I didn’t include pitchers in this analysis because there was no pattern among age groups that I could discern. The results were random.
So what have we got? We’ve got four age groups, from youngest to oldest, with an alternating up and down pattern of performing well under pennant pressure. Is this a meaningful pattern? Well, I don’t think so. I think it’s just normal variation, or variation explained by factors other than pennant pressure.
Perhaps 25-30-year-olds are more likely to have fluky first halves. Or maybe really young players naturally improve during the year more than older players do. Could be some injuries are making a difference, or that these findings are fundamentally related to the specific makeup of these teams.
I can’t explain the findings, and I’m not sure they’re meaningful anyway. The bottom line is that we can’t find any evidence in this study to support the idea that experienced players handle pressure better than young players do. Obviously, this isn’t a definitive work, and it probably won’t change many opinions. But beware of story tellers pretending to be truth seekers.
Maybe I should call that old friend of mine…
References & Resources
As a reference, here is a list of each team’s Win Shares Age this year. Win Shares age is essentially a team’s age weighted by the contribution of each player (as measured by Win Shares). There are several youth movements to note: the Giants are 3.2 years younger than last year’s team, the Twins are 2.5 years younger, the Dodgers are 2.3 years younger and the Rangers are 2.1 years younger.
Team WSAge MIN 25.7 TB 25.7 ARI 26.2 OAK 26.4 FLA 26.7 WAS 27.0 LAN 27.0 CLE 27.2 KC 27.2 TEX 27.2 ATL 27.3 PIT 27.4 LAA 27.4 COL 27.4 MIL 27.8 CIN 27.9 BAL 28.0 SF 28.1 STL 28.1 SEA 28.3 CHA 28.5 NYN 28.6 SD 28.7 BOS 28.7 CHN 28.9 DET 29.2 PHI 29.2 TOR 29.3 HOU 30.8 NYA 31.6