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Tuesday, December 04, 2007
Starters going deep
Discussions centered on the impact to the team, bullpen, player, on what happens when a starter does or does not go deep, and how to evaluate the player.
Here’s the post from MGL that is kicking this off:
(Note: the first few posts below were moved here from another thread.)
MGL:
BTW, how do we resolve that issue of the replacement pitcher not throwing 7 IP per game? Doing it that way, I get a 6.0 WAR for Santanta.
If the replacement pitcher only throws 5 IP and then a replacement reliever comes in for the other 2 IP that Santana would pitch, his WAR is only 5.4, a big difference.
IOW, here are the two ways to figure Santana’s WAR:
Method 1
Santana pitches 30 games, 7 IP per game, and allows 1.2 runs per 9, or .9333 per game (7 IP) less than the average league RA. For the remaining 2 IP per game, we assume league average RA. That is a .61 wp in a league where RA=4.7 and we use pythagorous. If a replacement pitcher pitches those same 7 IP per game, they will allow 1.2 runs worse than league average for those 7 IP, or .9333 runs per game worse than league average. Again, the other 2 IP are leage average RA. That is a .41 wp. For 30 games (210 IP for Santana or the replacement starter), that is a difference of .2 * 30, or exactly 6 wins.
Method 2
This is what happens in reality. The replacement pitcher only pitches 5 IP, for a total runs allowed of 1.2 * 5/9 worse than league average, or .67 runs per game. For the next 2 IP, a replacement reliever pitches .3 runs per 9 worse than average or another .067 runs per game worse than league average. The final 2 IP are pitches by league average pitchers (just like with Santana or with the replacement starter going 7 IP per game). That is a total of .733 rpg worse than league average, which is a wp of .428 rather than .41 when the replacement starter was going 7 IP. That is a WAR of 5.46 for Santana. That is with Santana going 210 IP but his “replacement” only going 150 IP, which as I said, is closer to reality.
So is Santana 6 WAR or 5.46 WAR. I submit that it is clearly #2. I think that Tango’s method would put him at 6 WAR, using something like method #1. Tango, what say you? Santana is 1.2 runs per 9 better than league average RA. He pitches 7 IP per game and 210 total IP. How many WAR is he if replacement is also 1.2 runs worse than league average RA. IOW, Santana allows 2.4 fewer runs per 9 than the league average. And league average RA per game is 4.7.