Superstition

Dallas's comeback win last night brought the series back to 2-2, and is promising to make this an especially memorable finals. People have torn apart Lebron and Jason Terry's play, while praising Dirk and Dwyane Wade. Turns out though, sports reporters have missed the single best predictor in the series: whether or not I wear my old Mavericks jersey. I wore it for games 1 and 3, but not for 2 and 4. Clearly me not wearing the jersey corresponds exactly to Dallas winning. Is there something there? Or is this an example of me having to much time to think of wacky things now that finals are done?

Traditionally, statisticians use 5% as the probability cutoff for correlation. If there's less than a 5% chance something would happen randomly, they assume it's a non-random process. The chances that my fashion choices would correctly predict 4 games in a row is just 1/16, or about 6.3%. That's not statistically significant, but it's close. If my jersey gets one more game right however, the odds move to 3.1%, a level that actually is significant. I won't be wearing the jersey for game 5 (go Mavs!) so a Dallas win will be more than just an important finals game, it'll be validation for all who ever believed that their particular scrap of cloth influences their team's play.

*Okay, clearly my shirt doesn't influence the game. What's wrong with this analysis?
First, I set the null hypothesis halfway through. Flip a coin 5 times, then hypothesize those results happen, and your test will be significant. If I say my jersey is a predictor one way or another, it could predict a Dallas win or loss, so 6 games is the level of significance, not 5.
Second, correlation does not imply causation, so it's possible some non-random third party is influencing both. Maybe I put the jersey on only when Dallas is losing (subconsciously). Or maybe Dirk watches what clothes I wear and then plays accordingly just to mess with my head.
Finally, even if something happens only 3.1% of the time from random chance, a random distribution will still give that answer 3.1% of the time. If you have 32 octopi picking 5 games, one of them is probably going to pick all 5 right. Then you can name him Paul and get the whole world to watch him.
Nonetheless, even though it's not true, I still kind of believe in this stuff. The truth is, I won't be wearing the Nowitzki jersey for game 5 because I want Dallas to win. But I won't be placing bets on it.

How many points for a win?

It's known among sabermetricians that if your baseball team can add 10 extra runs over a season you'll win another game (on average of course). This is useful because it's relatively easy to show that a player can add or remove runs from a team.

In basketball the corresponding number is 30 points (according to John Hollinger), which isn't quite as useful, but it's still not too hard to estimate the number of points a player adds.

I haven't found the number for football, so I decided to figure it out myself. Using linear regression on excel to relate point differential to wins I got the following data:

2009- 40 points

2008- 35.7 points

2007- 38.5 points

About 40 points in one season is a win? Sounds good to me. We'll show how useful this is later in the week.

Giants in the Playoffs?

For weeks now I've been waiting for the Giants to overtake the fluke Padres and to give me a chance to watch the MLB Playoffs in person. But as the season goes on, it's still not happening. Why? Turns out they've actually been a little unlucky, their run differential indicates they should have 76 not 75 wins. What are the chances that the Giants can overtake them?

Assuming pythagorean winning percentages (RS^2/(RA^2+RS^2) estimates winning percentage well, and predicts future success) play out for the rest of the season, it turns out that the Padres will probably win 7 games more than the Giants, and the Giants only have a 3.8% chance of winning the NL West.

Can I take Solace in the Wild Card? The Giants are tied for first place there, but the Cardinals who are a couple games back have been very unlucky this year. Doing a three team simulation between the Cardinals, Giants and Phillies the following Wild Card odds appear:

SFG: .337

PHI: .323

STL: .341

Turns out first place is only a slight advantage, it's actually a tight three way race. Which unfortunately means that I have at best a 37% chance of watching the Giants in the playoffs. At least it's better than the Cubs.

Self Lineup Runs

Who's the best mlb hitter this season? We looked already at Ken Griffey Jr.'s best years using a lineup full of Griffeys. Now, through yesterday, I've looked at the same statistic (which I've decided to call "Self Lineup Runs" or SLR. Please suggest better names.) for the best hitters in baseball. Here's a look at how those with the top 10 OPS fare in SLR:

	Player	Team	SLR
1	MORNEAU	MIN	11.016
2	YOUKILIS, K	BOS	9.819
3	CABRERA, M	DET	9.352
4	ETHIER, A	LAD	8.962
4	CANO, R	NYY	8.959
4	PUJOLS	STL	8.952
7	RASMUS, C	STL	8.296
8	ZIMMERMAN, R	WAS	7.923
9	KONERKO, P	CHW	7.893
10	ROLEN, S	CIN	7.421

Interestingly, for those who know the stats above, this is very closely related to OPS (On Base Percentage plus Slugging), but even closer to 2*OBP + SLG. This correlation was suggested in Wayne Winston's book Mathletics, and will be looked into more later.

Note: Although Ethier, Cano and Pujols don't have the same SLR, it's effectively a tie because of variance in the simulation. Running it again once actually put Pujols ahead of the other two, so it's too close to call.

Suns Efficiency

The Phoenix Suns have brought their series with the Lakers back to 2-2, and the debate is whether it's been their offense returning, or their new zone defense. Statistically, a simple way to look at it is to check whether the Suns have been scoring more, but a better was is to look at efficiency per possession. One example is to look at the Warriors this year, they had the second highest scoring offense, but only the 14th most efficient (I saw them, and they were definitely closer to 14th). So what's been the Suns' efficiency this season?

Efficiency	Game 1	2	3	4
Lakers	1.38	1.24	1.07	1.19
Suns	1.15	1.12	1.16	1.29

Efficiency	Lakers Win	Suns Win
Lakers	1.31	1.13
Suns	1.14	1.22

So while Los Suns have improved some offensively, it looks like the zone defense has made a big difference in the series. Or maybe its just the Lakers coming back to earth, the averaged 1.06 points per possession during the season.

Also of note is the run of injuries for Boston. Daniels hopefully will be okay, but Davis and actually Pierce may be of concern. It appears Davis suffered a pretty serious concussion, and that's something that can put people out for a couple weeks (even though he may feel fine physically). Paul Pierce's shoulder may also be a concern from when he collapsed on the floor earlier (not that rare, but important here). It looks on the replays like Pierce's shoulder subluxed, meaning it popped out for just an instant, then popped back in. That's a concern for two reasons.

1. It's gonna be weaker for a little while now (maybe a couple days). On his free throws right afterwards both of them hit the front of the rim.

2. It will be reinjured easier now, either subluxing again, or fully dislocating. I know this, because it happened to me recently.

Whether through injuries or zone defense, it looks like we now have two good conference finals on our hands.

Lebron A Bull?

Everybody from my Dad to Barack Obama has been campaigning for Lebron James to leave Cleveland and become a Chicago Bull. Today though, Jeff Van Gundy claimed that the Bulls still wouldn't be a real contender. So who's right? Fortunately John Hollinger has a statistic called Estimated Wins Added based off his PER stat. This is the number of wins (roughly) that a player would add over a replacement.

The Bulls should've won 36.1 games this year (They got lucky and won 41, but those sort of variations iron out over time). Luol Deng had an EWA of 7.4. Lebron's was 30.5. Putting Lebron in for Deng, and the 10-11 Bulls have 59 wins! Losing Salmons also will probably cost the Bulls an extra three wins from this year's team (he had a 5.9 EWA, against Hinrich's 1.0 over about 2/3 of the season).

What about other teams?

The Knicks (Lebron over Wilson Chandler) - 57 wins

The Nets (Lebron over crap)-46 wins

The Clippers (Lebron over more crap)-53 wins

The Heat (Lebron over Dorell Wright)-74 wins (umm, what? Okay, near extremes EWA isn't so good. Probably more like 65).

The Cavaliers (Lebron over Lebron) -59 wins.

So a simple Lebron substitution provides the following win totals:

Heat: 74 (65?)

Bulls: 59 (56?)

Cavs: 59

Knicks: 57

Clippers: 53 (more with Blake Griffin?)

Nets: 46

And purely for my amusement, the Bulls with Lebron and Chris Bosh?

+11 for Bosh. Bulls: 70 wins!

and Dwayne Wade (+20)?

Bulls: 90 wins!!!!!

Okay probably not. But it sounds like a record breaker. DWade for a midlevel exception?

The point is, JVG is right. For Lebron to really put a team over the edge he has to join a team that's already good (like the Heat) or he has to bring somebody like Bosh with him. He still helps though. I'm rooting for Lebron as a Bull.

Power Rankings

The penultimate column in my rankings is the power ranking of the team, but what does that mean? It's a concept that's similar to the Bill James's log5 concept (explained more here) and results in an easy comparison of teams. A sample calculation is as follows:

Team A PR of 2

Team B PR of 1

in a neutral site game, Team A's chance of winning if 2/(2+1) = 67% of games.

similarly, Team B's chance of winning is 1/(2+1) = 33% of the time they will win.

Looking at these rankings it means that Orlando (2.82) will beat New Jersey(.26) about 91.5 % of the time (that seams high. How does New Jersey only have 12 wins? They were a little unlucky this season, but we'll get to that later). Using these power rankings it's possible to calculate the likelihood of any team beating any other team.