What a Difference A Year Makes

Last season starting pitchers compiled a 4.41 ERA.  This season, starters are running an ERA of just 3.92, a very significant 11% improvement.  Reliever ERA has improved 5%, dropping from an average of 3.67 to 3.49.

Not surprisingly we've seen similar changes to batters.  Here are the league average stat lines per 550 AB:

ATB 13 - .275 / .338 / .393, 74 R, 18 2B, 4 3B, 12 HR, 71 RBI, 50 BB, 90 K, 4.7 R/G
ATB 14 - .266 / .325 / .375, 67 R, 17 2B, 3 3B, 12 HR, 65 RBI, 47 BB, 81 K, 4.2 R/G


What immediately comes to mind as the root cause is the focus on team defense plus the increased number of teams in the league.  This season we have 24 teams, while last season there were only 18.  


ATB 12 had twenty teams and ATB 11 twenty-four, adding them to the mix:


ATB 11 - .269 / .334 / .383, 71 R, 18 2B, 4 3B, 13 HR, 69 RBI, 51 BB, 90 K, 4.5 R/G
ATB 12 - .275 / .340 / .396, 74 R, 18 2B, 3 3B, 14 HR, 72 RBI, 53 BB, 93 K, 4.7 R/G

ATB 13 - .275 / .338 / .393, 74 R, 18 2B, 4 3B, 12 HR, 71 RBI, 50 BB, 90 K, 4.7 R/G
ATB 14 - .266 / .325 / .375, 67 R, 17 2B, 3 3B, 12 HR, 65 RBI, 47 BB, 81 K, 4.2 R/G



This is quite interesting.  While no definitive conclusion can be drawn from the above, in all likelihood the increased number of teams account for approximately half the reason pitching is improved across the board while the other half appears to be the effect of better defense and better drafting due to improved owner knowledge, thanks to more experience and of course the 79-resims.


ATB 12 and 13 averaged a .746 OPS with a similar number of teams.  ATB 11 averaged a .728 OPS, an 18 point improvement, that is almost assuredly due to the 24-team format.  The only aspect of the game that has changed between ATB 11 and this season, is the choice of players. This season, batters are averaging a .714 OPS, a 14 point drop from ATB 11.  Runs Per game follows a similar symmetrical drop from 4.7 to 4.5 to 4.2.


I don't think any of this means a whole lot, the playing field is level across all teams, but it is intriguing nonetheless.  One aspect that might change all this is the weather.  The DMB program accounts for increased hitting productivity as the weather warms.  There is a chance by the end of the year the average stat line will be similar to that of the previous two season, but I find it hard to believe it will fully make up the difference.