Wednesday 24 April 2013

Baseball By The Numbers

Yesterday’s post on baseball was poorly written, and should have made clear that the prices mentioned were the true prices for backing the home team in the middle of the respective innings. The win probabilities are of course significantly different at the top of the inning compared to the middle of the inning, assuming no change in score, with the home team’s chances increasing with each out of the top half of the inning. I have updated that post to make it clearer for future generations.

Our old friend BigAl, still looking in on the blog on a frequent basis for morsels of wisdom (there are a few if you pay attention) despite his oft dismissive and derogatory comments, (I forgot he was banned before I allowed his comments through, although they were actually quite sensible) suggests that “it’s a dangerous game simply applying the overall average to every game” but perhaps BigAl is no more well versed in the nuances of baseball than he is in the rules of cricket. The unique (other than softball) nature of the sport means that unless you have a good reason to believe that in any one game the long – very long in baseball’s case – established probabilities may be wrong, backing at greater than true (long-established) value is as dangerous as backing heads at greater than 2.0.

At the risk of educating BigAl and others who might otherwise take sub-value bets from or offer plus-value bets to the more knowledgeable of baseball bettors, the key player is the starting pitcher. One need look no further than the prices on each day of a series between two teams. A team is often odds-on for game one, yet the next day underdogs, and the only difference in line-ups is one player on each team – the starting pitcher. Teams generally have five starting pitchers, who rotate to start a game every fifth day. I'd like a job like that.

In the game as it is played today, it is unusual for the starting pitcher to throws more than a hundred pitches, (the number throwing more than 125 in a season dropped from 212 in 1998 to a nadir of 14 in 2007, although it has risen slightly since then) and it is in rare circumstances that he remains in the game in the later innings. If he does, the most likely explanation is that he is having a blinding game, perhaps he’s on a no-hitter or a perfect game, but either way, it is thus unlikely that the game would be tied were this the case. The highest pitch count for a starting pitcher since 2005 is 149, thrown in a no-hitter, which rather supports my theory.

Alternatively, the starting pitcher may also be left in the game ‘taking one for the team’, but this expression refers to the fact that the bullpen (non-starting pitchers) are being rested and saved for another day. Again in this scenario, it is probable that the game is all but lost, so the tied game state we need would not be an issue.

So BigAl’s cautionary words are certainly true in most sports, and should always be a consideration even in baseball, but my assertion is that the established probabilities are a solid starting point. If the value price is 1.63, then you would obviously need to factor in your individual edge and look for that price rather than take the bare minimum, but ask for 1.79 and you will get filled more often than you might reasonably expect. (1.79 is psychologically a better number for someone to lay, compared to 1.8).  

Home Team Odds - Bases Empty
The rather astute visitor fizzer555 follows my thinking too. In addition to understanding the true meaning of my poorly worded post, while agreeing with BigAl in principle, (not often a great idea), he was also sharp enough to observe that:
Cassini may be on to something though as by the time you get to the 7th innings the main reason for the fav/dog bias may be out of the game (i.e. the SPs) but I think the market may retain some fav/dog bias (gradually reducing across the 9 innings) that may not be justified. Don't have data to prove that but over 2 or 3 innings the hitting strength of each team is going to be very similar except for a few outliers (e.g. Miami, Houston low hitting) and similarly with bullpen pitching a lot of the teams will be in a narrow performance range.
Indeed, and I am beginning to wish I’d never let the cat out of the bag on this strategy! 

At least it makes for an interesting discussion and I have every confidence that the Donate button (top right) will be extra busy in the coming days as grateful readers once again line their pockets with extra cash, courtesy of Cassini’s shared wisdom. 

As the opportunity cost of my trading moves ever higher, I may give away even more such nuggets.

Of course, the reality could be that 99.9% of readers will move on, impatiently looking for an easier way to make money. Strategies that require a little research and patience don't seem to be too popular. 

I believe it was Shakespeare, in his play The Comedy of Errors, (not a play about BigAl's betting), who wrote: "You can lead a gambler to the edge, but you can’t make him leap".

1 comment:

AL said...

Hi Cass

I have now gone full time gambler/trader.

Please feel free to divulge any further edges as i have spare time.

yours faithfully
Little AL