Sunday, 31 August 2008

Trading Places

David Eckstein is off to Arizona, in return the Jays get Chad Beck. He's a 6'4" 23 year old RHP who spent most of the season in the California league (High-A, the equivalent of Dunedin) and is in his second professional season. The Jays drafted him out of high school (!) in 2004 but didn't sign him so he's been on their radar awhile. Looking at his stat page on, one notes that he handled lefties well, has very good ratios, and had a season of three excellent months and one very bad month. Observe the ERA and OBA pattern:

May - 1.46 - .222
June - 2.12 - .183
July - 8.36 - 3.33
August - 2.39 - .182

Which of these is not like the other?

If you look at the GO/AO ratio, you get a good lead on why. Beck gave up 5 HR in July and 3 the rest of the season. It's an easy guess he got bad location for a few games and elevated his pitches and got rocked for it.

Considering that a lot of Jays fans were saying "send us a bag of balls for him", I'd call this an impressive return. Let's see how much praise the Hated One gets for it.



Anonymous said...

Correct me if I am wrong WillRain, but I always see you showing bad months or bad streches for players. It's nice to look at, but unless its something that can be easily corrected or where a player shows growth I don't know what a team/player can do. Everyone has slumps, and the best players/teams are the ones that have fewer of these stretches. I think you mentioned that the Jays have had 2 poor strecthes of baseball and are playing very well beyond that. i don't have the stats (so correct me if I'm wrong) but it seems this happens every year and the better teams don't do this as much or at all...

The Southpaw said...

Well, without looking it up I can't provide specific examples but the problem, as a team phenomena, is that while a team like the Red sox might, at some point, go 3-11, they will also, at some point, go 9-0 or better, so they have a direct counter balance to the poor streak. (and then play maybe .580, or .600 ball otherwise)

The Jays have, the last few years, have tended to have the awful streak without the balancing hot streak (we are all aware of the road-block at five games)

On a player level, the intention of the analysis is not so much to say "this guy's ERA isn't REALLY 4.50" at all.

Rather it's to do two things. first, it tells you if the guy in question is consistently mediocre, or streaky and inconsistent.

Take Burnett for an example. Without looking it up his ERA is what, 4.48 or so right now? let's pretend that Jose Contrares has an identical ERA. now, in our example, let's assume (and this is the patter though I'm sure the numbers are off) that Burnett has had 25 starts, and got his ass royally kicked 6 times, and that in the other 19 games his ERA is 3.19, while on the other hand, Contrares has never given up more than five runs in a game, or less than 4.

Which guy is more likely to give you a chance to win a low-scoring game?

The second consideration is isolated streaks which don't reflect true value. this is, of course, highly speculative, but I think also informative.

Remember Aaron Hill's first full year? In late April he was sitting on something like .197 and in the midst of a streak that was like 6 for 46 or something. of course, he went on to have a fine offensive year from that point.
the thing is by the time you got to the ASB you could look back and see that Hill had sucked large for something like 16 or 17 games, and the other 70+ he did just what everyone hoped he would do.

In my opinion it is not irrational to say "what he did in the 70+ games is the 'real' Aaron Hill"

However, this sort of analysis requires two things - (1) that you have a MUCH bigger sample of the "true" stats than you do the exceptional ones, and (2) that there is no corresponding hot streak that needs to be isolated as well. and yes, btw, you can isolate an unreasonably good stretch and say "Player X isn't really as good as his overall number suggest"

So really, to put it in the context of Beck, it's simply a form of analysis - did this guy pitch in a mediocre fashion all year (and thus is a marginal prospect) or is he a guy who showed the ability to dominate, albeit inconsistently? (and this is a guy to keep your eye on)

Did I address what you were asking?

dave said...

Well, I don't know what Anon thinks but I liked the break down.

Quick question, though, I read a article a few months ago by Stephen Gould where he breaks down streaks and averages and argues that usually hot streaks or slumps are just an evening out of averages. Could you see Beck's bad month as possibly more of an evening out of his stats?

Anonymous said...

Glad to see you switched away from the black and white. I haven't visited this site in awhile, but I will come back more often. I like that you guys are active commenting on other blogs.
-brent in Korea

Anonymous said...

Glad to see you switched away from the black and white. I haven't visited this site in awhile, but I will come back more often. I like that you guys are active commenting on other blogs.
-brent in Korea

The Southpaw said...

Could you see Beck's bad month as possibly more of an evening out of his stats?

Not at that extreme. if it had been more like 5.5 or so then that's a normal variation, more or less....but not 8+

halejon said...

Stevie J was so ahead of his time..."The Book" is a great modern work mostly about that nature of stats- it expands it to show that even most player vs. player matchups can be explained by random variation, and in the short run even seemingly ridiculous hot and cold spells, periods of domination/inconsistency are often just what you should expect from random variation.

I think it holds less true for players who are developing, though- you really DO see pitchers in the minors figure something out and go on a tear for a while, unlike in the majors where other than some tweaks they have to be in comparison highly polished finished products.

I also think that unless a guy is striking out a ton of batters (for more than a month), 23 and in A ball is just way too old to consider him as a prospect for anything other than NL bullpen filler...