In light of the MLBs imminent decision to expand the playoffs by adding a wild card team, I wanted to take a look at whether or not they'd accomplish their goal of making the playoff races more exciting, thereby making more money.
Someone with a lot more time on their hands could study clinch dates, and schedules, but I don't have the time or the interest to do that. I'm going to look at record disparity, something I did in about 15 minutes.
This doesn't account for any sort of "incentive" and doesn't account for effort exerted by teams in a given situation.
All I did was look at the 32 wild card seasons (16 in each league), and the difference between the top three non-division winners wins. Call the best non-division winner WC1, the next WC2, and the third WC3.
I assumed that, if the difference in wins between WC1 and WC2 was LESS than the difference between WC2 and WC3, that adding an additional wild-card team that year would DETRACT from the "drama". Take 2011 in the NL. The difference between the Cardinals and the Braves was 1 game. The difference between the Braves and the Giants was 3 games. In this case, adding a playoff team would DETRACT from the Drama.
So, looking at all 32 season, we get some interesting results:
In the AL, Drama was added 12 times, and detracted 4. In the NL, Drama was added 8 times, and detracted 8. Overall, that's 20 seasons with more drama, and 14 seasons with less. About equal to my 50% a priori estimate. (Exactly equal, if you only count the real league)
So, what does this mean? Not much. There'll be an about equal amount of seasons with more drama and seasons with less drama. I'm sure there's some inherent bias in this quick study that I didn't consider, and maybe I'll expand on it later. Probably not.
Full season data available here: https://docs.google.com/spreadsheet/ccc?key=0AkGYe7flOFKPdE02b01UcndFWGIzdklITFBsYWZkcEE