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View Full Version : Crystal Ball End-of-Season ERAs

texasdave
05-31-2007, 05:13 PM
I ran across an interesting little toy on the Replacement Level Yankees Weblog and thought it was worth sharing. It is a formula that calculates the end-of-season ERA based on the present ERA of a pitcher, the expected number of additional innings to be pitched and the peripheral numbers needed to figure out a pitcher's FIP. FIP is much like DIPS. It takes the a pitcher's statistics that are not affected by the defense and it calculates the pitcher's ERA based on that. So basically this calculator takes the number of innings presently pitched at the present ERA and mixes it with the FIPS ERA based on how many additional innings each pitcher is expected to throw.

Pitcher TXIP ERA RXERA TXERA
Harang 220 4.22 3.32 3.65
Arroyo 220 4.01 3.69 3.79
Belisle 190 4.26 3.27 3.63
Lohse 190 4.59 3.85 4.11
Milton 100 5.17 4.59 4.77
Weath 72 4.13 2.29 2.90
Coffey 72 4.94 5.83 5.53
Stanton 54 5.41 3.42 4.08
Coutlan 54 4.91 4.76 4.81
Saarlo 69 7.04 4.90 5.61
Santos 90 4.45 6.54 5.84

The first column (TXIP) is a rough estimate of how many innings each pitcher is expected to pitch in 2007. The second column (ERA) is their ERA at the approximate 1/3 pole of the season. The third column (RXERA) is their expected FIP ERA for the remaining 2/3 of the season based on the pitcher's peripherals. And the fourth column (TXERA) is the mix of columns two and three. In other words it is the calculated end of season ERA. This is based upon the pitcher's peripherals staying at the same rate for the remainder of the season. Of course injuries, changes of role, trades and usage can affect these numbers, but it will be interesting to see how close this comes to the actual end-of-season ERA. All five Reds starters could likely see improvement. The bullpen is more of a mixed bag.

I ran all 16 NL teams through this same calculator. IMO the results seemed to lend some credence to the ERA calculator. The average team change for the rest of the season was pretty close at .04. I don't know much about DIPS and FIP etc. But they seem to be fairly accurate assessors of pitching ability.

ERA TXERA DIFF
SDP 2.97 3.17 0.20
NYM 3.40 4.06 0.66
ARI 3.70 3.98 0.28
SFG 3.75 3.99 0.24
MIL 4.04 4.05 0.01
CHC 4.09 4.22 0.13
ATL 4.15 4.15 0.00
FLA 4.38 4.38 0.00
HOU 4.39 4.40 0.01
PIT 4.51 4.55 0.04
WSN 4.51 4.66 0.15
CIN 4.62 4.16 -0.46
PHI 4.62 4.53 -0.09
COL 4.65 4.46 -0.19
STL 4.69 4.46 -0.23

AVERAGE +/- 0.04

Once again the first column (ERA) is the present ERA. The second column (TXERA) indicates what the calculator thinks the ERA will be at the end of the year based on a team's pitching numbers. (insert injuries, etc disclaimer here) The numbers show that the Reds pitching staff should rebound in the final 2/3s of the season. That, based on HR, BB and K rates, better days should be ahead. Note: a negative number in the DIFF column means ERA improvement is likely for that particular team. That is always a good thing. Teams that may tumble a bit include the Mets, Giants, the D-Backs and the Nats.

klw
05-31-2007, 06:23 PM
Interesting. I was just looking at stats over at ESPN and thought it showed that similar possibilities of improvement. Unfortunately I hadn't looked here so I started another thread. Now it would seem that either the pitching will improve or that for some flaw in the makeup in the staff it will underperform for the whole season.