Given my newfound data on player retention, I thought it might be interesting to look at whether retaining young talent leads to winning teams. I looked at how long each franchise does on average in retaining the players that first reach the majors with them.

Below are the results sorted from highest to lowest. Keep in mind that the newer expansion teams will have lower numbers given that they haven't had time to build up a history:

Franchise	Avg Team Yrs	Avg Total Yrs	%	First	Last	PCT
Houston Astros	3.22	5.61	57.49%	1962	2005	.500
New York Yankees	3.09	5.79	53.43%	1901	2005	.567
San Francisco Giants	3.07	5.48	56.06%	1883	2005	.540
Los Angeles Dodgers	3.05	5.67	53.89%	1884	2005	.524
Milwaukee Brewers	3.03	5.09	59.57%	1884	2005	.472
Detroit Tigers	3.00	5.08	59.07%	1901	2005	.505
Los Angeles Angels of Anaheim	3.00	5.61	53.51%	1961	2005	.490
Toronto Blue Jays	2.99	5.78	51.70%	1977	2005	.494
Kansas City Royals	2.95	5.09	57.98%	1969	2005	.491
Minnesota Twins	2.95	4.62	63.69%	1901	2005	.480
Boston Red Sox	2.94	5.02	58.49%	1901	2005	.515
Cleveland Indians	2.86	5.30	53.95%	1901	2005	.511
New York Mets	2.86	5.99	47.65%	1962	2005	.474
Pittsburgh Pirates	2.84	5.16	55.06%	1882	2005	.508
Texas Rangers	2.83	5.43	52.19%	1961	2005	.467
Chicago White Sox	2.82	4.60	61.28%	1901	2005	.506
Atlanta Braves	2.77	4.83	57.36%	1876	2005	.499
San Diego Padres	2.72	5.15	52.81%	1969	2005	.459
Seattle Mariners	2.70	5.11	52.89%	1977	2005	.470
St. Louis Cardinals	2.67	5.07	52.71%	1882	2005	.517
Cincinnati Reds	2.67	5.13	51.96%	1876	2005	.506
Chicago Cubs	2.66	5.18	51.46%	1876	2005	.514
Oakland Athletics	2.59	4.61	56.17%	1901	2005	.485
Baltimore Orioles	2.54	4.57	55.55%	1882	2005	.482
Washington Nationals	2.49	4.89	51.03%	1872	2005	.469
Florida Marlins	2.47	4.36	56.59%	1993	2005	.472
Tampa Bay Devil Rays	2.47	3.18	77.49%	1998	2005	.401
Philadelphia Phillies	2.45	4.37	56.18%	1883	2005	.468
Colorado Rockies	2.29	3.45	66.55%	1993	2005	.465
Arizona Diamondbacks	2.07	3.16	65.57%	1998	2005	.503

A cursory look at the list seems to indicate that winning teams retain young players longer. However, when I ran the numbers I found that the correlation isn't very strong at all (coefficient of 0.4546). Actually, the total years that the players these teams developed (though didn't necessarily spend with the given team) correlate to their winning percentage slightly better (0.5056).

OK, maybe I'm comparing apples to oranges. What if we divvied the up the team stats by decade? The teams that retained young talent best did have some very good results. The Yankees of the '30s, the Reds of the Sixties and Seventies, the Seventies Royals, the O's in the '60s, etc.:

So how well does retaining one's prospects correlate to winning when the data are divided up by decade? Even worse than the overall stats (coefficient of 0.1598).

Well, my next thought was that maybe we need to limit some of the data. The data from the current data is largely meaningless given that it'll be incomplete for another decade or so. Also, the nineteenth-century data are much lower given the volatility of the times. I limited the data to 1900-2000 only. The results were…(drum roll please)…not a whole lot better (0.3198).

So what does it all mean? I'm going back to the drawing board, but by the looks of things teams that held onto their young players longer did not necessarily lead to on-field success. Given that teams have tried to sign up their youngsters a la the Indians in the Nineties, this seems counterintuitive. Isn't the whole idea behind restricting free agency to players with six years of major-league experience and arbitration to those with three based on this theory?

Maybe it's not retaining the most youngsters for the longest that helps teams win. Maybe it's retaining the best and being able to evaluate that correctly that helps teams win.