MLB: Quantitative handicapping of rookie pitchers

[fun160]

Question for TomG and other geeks:

What do you number crunchers do when a rookie pitcher is starting? What xERA (or other value) do you use when faced with small/zero sample size? How does it affect your line calculation? What about your Totals calculation? Thanks in advance.

[JoshEngleman]

I can't speak for anyone else, but when guys are making their debuts, or only have a a few starts under their belts, I just simply stay away from the game. In the future, I'm probably going to add in PECOTA forecasts and see how they hold up but for now I'm fine with staying off of those games. There's plenty of other games to bet on each day. There's no sense in taking a game that I am lacking information on.

[TomG]

I used to pass on those games, but I'm starting to think doing so is giving the books too much credit. The books have to throw out their best guess and I don't see why we can't guess along with them. We don't have to be perfect, just better on average than the books. Some things I use to get a better estimate than the books...

1) PECOTA projection
2) A DIPS ERA (excluding hits) as this should converge faster than xERA or ERA
3) When all else fails, plug in several different ERA estimates to test the line for value. How high/low do you have to give him an ERA in order for the game to become betable? Be conservative of course.

Tomorrow we have four pitchers (Shane Youman, Tim Redding, Jesse Litsch, and Ryan Feierabend) who have all pitched less than 50 innings. I'll likely be taking Toronto (once again) and Jesse Litsch... and that's even after giving him a conservative 6.0 ERA!

[rjp]

I think it was Mike Lee's book that addressed this... but don't quote me on that.

Basically the theory is that these guys wouldn't be pitching if they didn't have the goods. Why ruin a good prospect when you can sign or call up an old guy to take a shilling every few outs?

No idea how to quantify this, but I'd say teams facing these pitchers are likely overvalued by the general public.

Oh, and I'm referring to pitchers making their first major league start. [img]/images/graemlins/wink.gif[/img]

[dudeimstoked]

i would either use pecota or stay away from them all together.

[centris]

In this study David Luciani compared the AAA and MLB stats of players who had a significant number of IP or AB in both leagues in the same year (I think he used four years of data from 1994 to 1997). He found that in ML pitchers had 110% the H, 157% the HR, 125% the BB, and 75% the K of their AAA level. So you could use the AAA stats apply the conversion from the article and get an estimate for xERA or FIP or whatever.

link

[fun160]

[ QUOTE ]
In this study David Luciani compared the AAA and MLB stats of players who had a significant number of IP or AB in both leagues in the same year (I think he used four years of data from 1994 to 1997). He found that in ML pitchers had 110% the H, 157% the HR, 125% the BB, and 75% the K of their AAA level. So you could use the AAA stats apply the conversion from the article and get an estimate for xERA or FIP or whatever.

[/ QUOTE ]

Thanks, interesting stuff. I wonder if he accounted for park differences, which can have a dramatic effect on MLEs.

[ QUOTE ]
I used to pass on those games, but I'm starting to think doing so is giving the books too much credit. The books have to throw out their best guess and I don't see why we can't guess along with them. We don't have to be perfect, just better on average than the books...When all else fails, plug in several different ERA estimates to test the line for value. How high/low do you have to give him an ERA in order for the game to become betable? Be conservative of course.

[/ QUOTE ]

Thanks, TomG, I love this approach.

Have you kept track of your handicapping when rookie pitchers are involved? It would be interesting to track how your "guesses" compare to those of our opponents...uh, make that bookies and the public.