Well it has been way too long since I posted a mini article for BCB. I have been a bit busy with the PITCHf/x stuff and the hardballtimes stuff but really this is where I got started and I really appreciate everyone here who read my early stuff and had excellent comments about my work. So today I would like to look at the Cardinals early start to try to determine how much luck has been involved and how much of it is skill.
As you know, the Cards are off to a 18-11 start but have generally played some weaker opponents and have played 18 games at home. Still, if you look at BP's postseason odds and their postseason odds with PECOTA helping the difference is night and day. When you just look at their 3rd order winning percentage (Pythagorean record on steroids) they appear to be a .523 team. If you ask PECOTA though they are a .463 team. The difference is over eight wins over the rest of the season so determining which team the real Cardinals are would be a great help in finding out if they will make this a three team race.
A good way at looking at how a team will perform is first looking at how it has performed. As I said, the Cards are off to a 18-11 start. One of the things we can do is determine how likely it is they would start that hot or better assuming each of the winning percentages. Obviously, the start will be more likely if we assume they are a .523 team but by how much? Is this start just too unlikely for a .463 team?
So I wrote a quick Monte Carlo that basically flips weighted coins. I plugged in the Cardinals winning percentages and their opponents winning percentages and then assumed a +3% for the home team. I am running a million seasons to this point. So to start I plugged in a winning percentage of .5 with no home field and I got 13.2%. So if every game the Cards played was a coin flip there is a 13.2% chance they would be 18-11 or better at this point. If I use just the 3rd order percentage for every team I get 22.5%. With the PECOTA help I get 8%.
So what do these numbers tell us? Well, no matter which Cardinal team you think they are they are playing over their heads right now. You have to assume they are just a tick over 60% for this record to be more than 50% likely which I think even hard core Cardinal fans would have trouble believing. The question is how over their heads they are right now?
While 8% is still a possibility it is starting to get small enough that is seems more likely that PECOTA has got it wrong on the Cardinals and they really are a better team than .463. Are they really a .523 team or a .500 team is still something that is hard to tell but I think it is time to consider them real contenders. Maybe they aren't as good of a team as Brewers or Cubs but even if they play .500 from here on out that should be good enough to keep them in contention for most of the year. So I think it is time to include the Card when discussing who will win the Central this year.