At What Age is a Hitter’s Projection No Longer Reliable?

I blame my podcat mate Rob Silver for today’s study. First, he stated this:

And then he said this:

Of course, players age. Some quickly. Some not as fast. While few hitters remain productive into and past their mid-30’s, I needed a simple rule on how to deal with these vets. I found one and since I need to provide content to be paid, so does the world.

To perform the analysis, I examined how hitters met their projections as they crept up in age. To do this, I took a hitter’s Steamer projection (back to 2010) and found how close it was to that season’s actual results. And I’m also including the previous season’s results. It was not obvious I needed this value. It was pivotal to finding a simple solution and helps verify some of the work from The Process.

Note: For player valuation, I’m using my 15-team 5×5 NFBC valuation from last season.

I grouped the players who projected to produce $15 or more in return by age. Then I found the median and average amount this group missed their projections by. Also, I divided this group by those who were projected to exceeded or not meet their previous season’s production. And here is the data.

How Much to Hitters Fail to Meet Projections By
Overall Higher Expectation Lower Expectation
Age at Projection Median Diff Average Diff Median Diff Average Diff Median Diff Average Diff
23 -$3.0 -$3.3 -$6.0 -$5.5 $0.4 $0.4
24 -$4.7 -$6.4 -$5.2 -$7.8 -$4.5 -$5.0
25 -$2.9 -$3.8 -$2.5 -$3.8 -$3.4 -$3.4
26 -$3.5 -$4.9 -$7.2 -$7.6 -$1.3 -$1.3
27 -$0.1 -$2.6 -$1.9 -$3.3 $0.1 $0.1
28 -$4.6 -$6.9 -$4.8 -$9.5 -$4.1 -$4.1
29 -$1.8 -$2.0 -$1.3 -$2.6 -$2.1 -$2.0
30 -$1.1 -$2.0 -$2.7 -$5.7 -$0.6 -$0.6
31 -$4.8 -$6.9 -$4.8 -$8.5 -$6.3 -$6.3
32 -$4.4 -$4.7 -$8.3 -$6.9 -$1.5 -$1.5
33 -$6.4 -$4.1 -$15.7 -$12.0 $1.1 $1.1
34 -$3.0 -$4.7 -$6.5 -$6.4 -$1.2 -$1.2
>=35 -$3.8 -$4.8 -$5.6 -$6.6 -$3.8 -$3.8
>=36 -$3.5 -$4.5 -$4.5 -$7.1 -$3.4 -$3.4


The Steamer projections are a little ambitious but are consistent over the different ages by missing on average (blue line) between -$5 and $0. Also, if a hitter is projected to outperform their previous season, they will, on average, miss on their projection by a larger range. This finding agrees with the study in The Process.

One anomaly does stick out. From age 32 and older, the difference between those expected to beat previous production and those that don’t get wider (the difference between yellow and red line). For the age-32 or older batters, the two groups differ by $6.30. For those 31 and younger, the difference is $1.7.

With this analysis, I am just not going to give any top hitter over the age of 31 any more credit than they did the previous season. Now, as the talent pool thins, I’ll gladly take a chance on these distinguished gentlemen, but not until then. I can’t have the core pieces on my team imploding on me.

Using our current Depth Chart projections, here are the $15 or better hitters who are going into their age-32 or older, their 2019 production, and their projected 2020 values.

2020 Top 32-Years or Older Projected Hitters
Name Age 2019 Return 2020 Projection Difference
Justin Upton 32 -$5.2 $15.6 $20.8
Andrew McCutchen 33 -$3.6 $15.1 $18.6
Khris Davis 32 $4.9 $20.7 $15.8
Lorenzo Cain 34 $9.8 $16.9 $7.1
J.D. Martinez 32 $28.4 $32.5 $4.1
Ryan Braun 36 $16.2 $19.1 $2.9
Justin Turner 35 $15.5 $17.6 $2.1
Edwin Encarnacion 37 $15.6 $16.5 $1.0
Tommy Pham 32 $20.2 $21.1 $0.9
Paul Goldschmidt 32 $21.9 $22.5 $0.6
Nelson Cruz 39 $26.8 $26.8 -$0.0
Josh Donaldson 34 $22.5 $20.9 -$1.6
Yuli Gurriel 36 $25.0 $21.2 -$3.8
Jose Abreu 33 $26.0 $21.9 -$4.1
Michael Brantley 33 $21.4 $17.4 -$4.1
Charlie Blackmon 33 $27.7 $22.8 -$4.8
Carlos Santana 34 $25.9 $18.9 -$7.0

The one name which immediately comes into play would be Martinez. Projections have him producing $32 of value but he was just worth $28 last season. For someone going in the second round, I’m going to give myself a little cushion to work with him since these veterans normally produce at a $26 range ($32-$6).

I was getting to the point where I was afraid to roster any older hitter so I would just stay away and miss out on some bargains. Instead, I’m just more cautious of them by limiting my expectations to their previous production levels. By following this rule, I’m hoping to limit the downside while not completely ignoring older hitters.

Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR twice, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.

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4 years ago

Interesting stuff. And more importantly, very useful.

I wonder about a focused look at this group of 32+ year-olds projected to beat their previous season output. Whether the reason for their low output in previous year was due to injury, or due to poor performance.

We know there are well developed aging curves, but they’re mostly tuned to adjust based on performance, rather than injury. There are so many types of injuries that it’s hard to make an algorithm, so we’re left to basically look at their actual performance. Therefore, I have a feeling Steamer would be better at projecting the guys who were mostly healthy but just performed below expectations (K. Davis, Cain, JDM, Goldy, etc), vs the guys who were injured (Upton, McCutchen, etc). Because for older players, injuries may be harder to come back from, and start to pile up. Then again, the guys who had poor performance might have been facing nagging minor injuries more so than earlier in their career. For example, I know Edwin has had ongoing thumb problems for at least 5 years, now. Donaldson also has the calf issues that bothered him for 2 years.

I avoided Upton last year for this reason (his injury was way more serious and chronic than most people thought) and I’ll do so again.

I’ll also probably be more cautious in general of older players who we might be expecting too much from, especially in terms of speed. I can easily see Pham and Cain’s SB totals falling off a cliff pretty soon.

Once again, great work here, Jeff. I look forward to reading The Process over the Christmas break.

4 years ago
Reply to  Rotoholic

Cain’s sort of did. He was incredibly unlucky late last year however, so maybe…? Cano is sort of the same sort of thing. He is free in drafts basically, and is another guy who basically hit the ball incredibly hard last year and put up horrible numbers. It might have something to do with steroids, it might not, but when you look at his career wRC+ line every single year where it dips hard it comes back with a vengeance the following year. In the mid 300s in ADP you don’t really have to risk a thing to draft him either. He seems like a very good pick in that range as a backup in DC’s.