Do Speedsters age differently than Leadfooters?

by Tangotiger

Baseball skills follow a certain aging pattern. They appreciate considerably in the early twenties, hover at a peak in the late 20s, slowly start to erode in the 30s, and quickly diminish in their late 30s. This is intuitive to most people, and can be substantiated in a study I published here: Age Factors for Hitting Events . That study further breaks down how each of the hitting components ages. Speed dimishes starting at age 24, while walks dimish starting at age 32. This again makes sense.

But can certain styles of hitters age differently? That is, is it possible that a speedster's hitting skills diminish at a different rate from the hitting skills of a leadfooted hitter?

For this study, I looked at all hitters born between 1941 and 1960, and looked at their career totals up until age 30 (with a minimum of 2500 PA). I selected the 20 best hitting speedsters from that list. Here they are:

Best-hitting speedsters, born 1941-1960, up to age 30
Raines, Tim
Henderson, Rickey
Bonds, Bobby
Morgan, Joe
Cedeno, Cesar
Gibson, Kirk
Van Slyke, Andy
Dawson, Andre
Sandberg, Ryne
Smith, Lonnie
Garr, Ralph
McBride, Bake
Richards, Gene
Molitor, Paul
LeFlore, Ron
McGee, Willie
Wilson, Willie
Kelly, Pat
Mumphrey, Jerry
Samuel, Juan

No big surprises here. The usual suspects like Tim Raines, Rickey Henderson, and Ron Leflore are here.

Working from the same list, I selected each hitter's leadfooted twin. That is, which player has the same hitting style and same level of offense as Tim Raines, but doesn't have his speed? Based on similarity scores I am developing, the answer to that question is Wade Boggs. Here are the leadfooted hitting twins to our speedsters:

Best-hitting speedsters, born 1941-1960, up to age 30, and their leadfooted twins
Speedster	LeadFoot
Raines, Tim	Boggs, Wade
Henderson, R	Singleton, Ken
Bonds, Bobby	Luzinski, Greg
Morgan, Joe	Davis, Alvin
Cedeno, Cesar	Watson, Bob
Gibson, Kirk	Aikens, Willie
Van Slyke, Andy	Evans, Dwight
Dawson, Andre	May, Lee
Sandberg, Ryne	Garvey, Steve
Smith, Lonnie	Grubb, Johnny
Garr, Ralph	Oliver, Al
McBride, Bake	Braun, Steve
Richards, Gene	Hunt, Ron
Molitor, Paul	Montanez, Willie
LeFlore, Ron	Chambliss, Chris
McGee, Willie	Tabler, Pat
Wilson, Willie	Piniella, Lou
Kelly, Pat	Smalley, Roy
Mumphrey, Jerry	Bell, Buddy
Samuel, Juan	Parrish, Larry

I excluded catchers from this list, because catchers have other things working against them that our speedsters don't have. Again, while we don't have many surprises, it is an interesting list. Andy VanSlyke without speed? Dwight Evans. Ryne Sandberg without speed? Steve Garvey. Remember, the comparisons are only made with stats up to age 30.

Here are their average totals

Average of players born 1941-1960, up to age 30
Style	  PA 	 G    AB    R 	 H    2B  3B HR  RBI SH	 SF SB 	 CS  BB  IBB HBP SO 
Speedster 4,349 1,034 3,901 628 1,117 180 52 90  425 21	 28 295  84  395 34  27	 597 
Leadfoot  4,253 1,055 3,789 508 1,080 194 23 106 516 23	 35 26 	 25  398 45  31	 528 

The Speedsters had almost 100 more PA, but 21 less games. This makes sense as the Speedsters have many leadoff hitters that would accumulate many more 5 PA games than their leadfooted twin. All in all, except for the SB, a pretty good matchup. Now, what happened to these players after the age of 30? Here are their totals

Average of players born 1941-1960, after age 30
Style	  PA 	 G    AB    R 	 H    2B  3B HR  RBI SH	 SF SB 	 CS  BB  IBB HBP SO 
Speedster 3,307  848  2,912 459  819  142 26 78  369 12  28 147  45  347  27  20 448 
Leadfoot  2,938  773  2,609 341  729  130 12 76  366 8   25 13   14  289  35  15 347 

The speedsters average 75 more games for their post-30 career. Hardly a significant advantage. Pro-rating all their stats to 600 PAs, this is how these players compare.


Age	   G AB  R  H    2B  3B HR  RBI SH SF SB CS BB  IBB HBP SO 
Pre-30   143 538 87 154  25  7  12  59 	 3  4 41 12 54 	 5  4 	82 
Post-30  154 528 83 149  26  5  14  67 	 2  5 27 8  63 	 5  4 	81 


Age	   G AB  R  H    2B  3B HR  RBI SH SF SB CS BB  IBB HBP SO 
Pre-30   149 535 72 152  27  3  15  73 	 3  5  4  4  56  6  4 	75 
Post-30  158 533 70 149  26  3  15  75 	 2  5  3  3  59  7  3 	71 

The speedsters pretty much had the same stats/600 PA. A few less singles, a few more HR, and a few more BB. Their speed numbers came down substantially. All this is as you'd expect from any hitter.

The leadfooters actually look more consistent than their speedtwins. But again, the numbers are so close, that you would expect to see minor deviations as these.


The results of this particular study (granted that there are variables, like position, that were not accounted for, and the sample size is somewhat small) shows that speedsters and leadfooters show no difference in their aging patterns. There seems to be a small tendency that a speedster will play a few more games than the leadfooter, but this difference is probably linked to the small sample size, and the effect that one player would have on the whole group. Therefore, the search for a hitter's "twin" does not appear to have predictive value. Similarity scores should not be used for projections.