Average age by fielding position

I was asked to compare two imaginary players. Both of them are 26-year-olds, and one of them plays 2B/3B while the other plays LF/RF. I wrote that they were similar in many aspects, including their ages, but then I realized I underestimated the fact that a 26-year-old playing infield may not be as young as a 26-year-old playing corner outfield.

I tried googling an average age of players by their fielding positions, but could not seem to find it so I decided to compute it on my own. From the Baseball-reference, I looked up each team's page, went to fielding tab to find out which players played in which positions in 2014. Conveniently, it had players' ages right next to their names so it saved me lots of time.

When averaging, I weighted by the number of innings they played. I figured if a 20-year-old played 161 games and a 40-year-old played 1 game, it wouldn't be fair to say the average is 30. Here are the results:

	DH	P	C	1B	2B	3B	SS	LF	CF	RF	OF	ALL
AL	31	28.34	28.32	29.41	28.38	27.05	28.34	29.11	27.18	29.36	28.55	28.65
NL	30.12	28.46	28.85	29.07	27.78	28.36	26.91	28.08	27.15	28.75	27.99	28.17
ML	30.95	28.41	28.59	29.25	28.08	27.72	27.63	28.6	27.17	29.06	28.28	28.42

Numbers in red mean they are older compared to their respective positions in the other league; backgrounds in gray mean that they are older than the overall league average.

1. DH and 1B are the oldest for both league, as expected.

2. CF is younger than LF and RF, also as expected.

3. 3B is relatively old in NL. My guess is that since NL don't have DH, the third base is another source for (veteran) power hitters.

4. 2B/3B is younger than LF/RF, meaning even if both of my imaginary players are 26, the one playing 2B/3B is less likely to stay in his position as he gets old I think.

5. While digging up the data, I noticed another interesting fact:

	DH	P	C	1B	2B	3B	SS	LF	CF	RF	OF	ALL
AL	218	393	59	98	82	83	66	128	81	123	332	1331
NL	78	352	54	91	92	85	68	112	78	103	293	1113
ML	296	745	113	189	174	168	134	240	159	226	625	2444

These are the number of players played in each position in 2014. There are overlaps.

5a. Small number in DH for NL is because they did not play many games with the DH rule; only interleague away games.

5b. Teams used the least number of players in the center line, C - SS - CF. I guess players in those positions are the best defensively and hard to be replaced. Maybe in the future I'll take a look at the percentage of games that the primary fielder take the position, by each position. I would expect a fair number of platoons in 1B and/or LF/RF, but not many in SS/CF.