How does player birthplace affect performance?

"You cannot walk off the island" is a quote said by someone long ago about how to go from being an amateur baseball player in the Dominican Republic to being a professional one in the United States of America.  It is a perspective that is slowly, quite slowly, changing as the DR is incorporating more players leagues to give prospects in game experience as opposed to solely engaging in workouts.  Recently, Jorge Arangure Jr wrote another fascinating article on this.

It made me think...historically, how does the country of origin affect the "average" baseball player.  I decided to review the past 20 years for players who have accumulated at least 1000 games to see what successful players from these countries have been able to accomplish on average.

1993-2012		Players with at least 1000 games
	#	BB%	SO%	SB%	AVG	OBP	SLG
USA-St	163	9.7	15.8	71.9	.277	.341	.453
DR	28	8.0	15.0	70.7	.281	.333	.465
USA-PR	15	9.2	16.0	70.7	.277	.338	.458
VZ	16	8.4	13.0	69.9	.278	.332	.422

First off, I used 15 players as a cutoff point (small sample size alert) and I included Puerto Rico as a country of origin even though they are American through and through.  Anyway, what we see is that these populations do seem to carry some of the stigma.  Dominican players do tend to walk less than the average American.  Venezuela's youth league system is often mentioned in how they produce players with better skills levels, but the difference in walk rate does not seem like much and it gets lost when you fact in batting average for on base percentage.

This made me wonder though if by choosing 1000 games as a cutoff point that I am ignoring players with attributes that prevent them from having a career at that length.  Furthermore, it may also be that by including players in general that the numbers are being washed out due to a different kind of selection bias.  It has been often mentioned that there is a dearth of American shortstop prospects and the reason for this is that these big, athletic people who could play shortstop are being pushed over to sports like basketball (as a point guard or shooting guard) or football (any skill position) where there are institutional advantages.  In other words, Americans who can excel at shortstop will chase athletic opportunities that offer better scholarships options at the college level.

In 2012, 11 of 23 (48%) shortstops with over 100 games played were born in the USA.  In contrast, 22 of 29 (76%) first basemen with over 100 games played were born in the USA.  In 1991, American born SS were 17 out of 27 (63%) and American born 1B were 21 out of 27 (78%).  This is only two data points (a later post will explore this more fully), but it seems to suggest that position profiles differ by country of origin.  Therefore, it might make more sense to compare players by position and not by overall population.

Below is a comparison between the countries and the average SS with at least 100 games played from those countries.  Puerto Rico was not included because they had too few players meeting this description.

1993-2012		Shortstops with at least 100 games
	#	BB%	SO%	SB%	AVG	OBP	SLG
USA-St	55	7.8	14.7	72.0	.269	.319	.404
DR	26	6.3	13.7	70.2	.271	.310	.397
VZ	12	7.1	12.7	69.4	.267	.311	.375

The pattern for an average player remains.  Dominicans walk less than both Americans and Venezuelans, but OBP is essentially the same for both Dominicans and Venezuelans.  My next thought was whether or not there was an issue here with me not measuring fielding.  However, using rWAR's fielding component I devised a fielding runs by 150 games (using the assumption that 4.2 plate appearances equaled a game), Americans had a 1.4 runs above average, Dominicans were -1.2 runs above average, and Venezuelans were 2 runs above average.  It does not appear that lesser offensive production is accepted in exchange for defensive aptitude.

Conclusion
Historically, it appears that there are indeed differences in performance based on player origin.  The above study does not determine why this is so.  Speculation suggests that there are existing prejudices in the developing country and/or in the developing organization that encourages some types of performance while ignoring other types of performance.  An example of this is that there is about 9:1 ration of small white guys being called gritty as opposed to small guys of other ethnicity.  Personal anecdotal experience has informed me that there still is a contingency in professional baseball that tends to undervalue talent in white prospects and skills in black prospects.  Likewise, athletes from other countries are often maligned as being unintelligent which often is simply a product of English not being a first language as well as organizations having little interest in providing academic education to 16 year olds that they sign.  Of course, this is speculation based on anecdotes.

Another point to consider is that this is a historical study.  It informs us a little bit, but not excessively, about what will happen from 2013 to 2032.  Youth leagues are beginning to sprout up in the Dominican Republic along with talk of MLB focusing more on the island.  Additionally, more and more organizations are starting to realize that foreign born players often need more assistance in acclimating to new environments and have been developing more useful instruction in language and cultures in order to make it easier on players to focus on developing their baseball abilities.