APBRmetrics

**back2newbelf** · Joined: 21 Jun 2005 Posts: 250

Using SRS as indicator for team strength, then simulating 10000 7-game series with the WPyth% formula with an exponent of 9.5
-------------------------
-------------------------
Cleveland Chicago
41 29.58%
42 19.49%
40 19.36%
43 15.99%
34 6.22%
24 5.46%
14 2.65%
04 1.25%
--------------
84.42 % 15.58 %
-------------------------
-------------------------
Orlando Charlotte
41 24.46%
42 20.06%
43 18.08%
40 14.69%
24 8.64%
34 8.13%
14 3.89%
04 2.05%
--------------
77.29 % 22.71 %
-------------------------
-------------------------
Atlanta Milwaukee
41 19.21%
43 18.95%
42 16.48%
24 13.02%
34 11.97%
40 9.75%
14 6.93%
04 3.69%
--------------
64.39 % 35.61 %
-------------------------
-------------------------
Boston Miami
43 18.26%
41 17.82%
42 15.97%
24 14.93%
34 12.66%
14 8.49%
40 7.59%
04 4.28%
--------------
59.64 % 40.36 %
-------------------------
-------------------------
Los Angeles Oklahoma
43 18.46%
24 15.81%
41 15.77%
42 15.13%
34 13.1%
14 9.71%
40 6.7%
04 5.32%
--------------
56.06 % 43.94 %
-------------------------
-------------------------
Dallas San Antonio
24 20.97%
14 15.28%
43 15.1%
34 14.76%
42 10.52%
04 9.9%
41 9.78%
40 3.69%
--------------
39.09 % 60.91 %
-------------------------
-------------------------
Phoenix Portland
43 18.06%
24 16.5%
41 15.98%
42 14.69%
34 13.3%
14 9.9%
40 6.82%
04 4.75%
--------------
55.55 % 44.45 %
-------------------------
-------------------------
Denver Utah
24 19.77%
43 16.67%
34 14.2%
42 12.53%
14 12.52%
41 11.73%
04 7.54%
40 5.04%
--------------
45.97 % 54.03 %
-------------------------
-------------------------

There are some obvious questions and problems:
-Clevelands' rating would probably have been higher if LeBron didn't sit out the last couple of games
-How good is Milwaukee without Bogut? I think they're still pretty good
-Does Oklahoma really have a 44% chance to beat L.A.? The Lakers' SRS rating is just not very good. How much does the absence of Bynum have to do with it and when is he coming back? Can Kobe return to form?
-Is Dallas' true rating higher because of the trade? I doubt it. I really don't like Caron Butler
-How good is Portland really? Their SRS rating includes lots of games with Oden/Joel/without Batum. Can Roy play?

Things that people thought to be of importance but (I believe) were proven insignificant:
-experience, which many people will probably use to make a case for L.A. vs Oklahoma
-performance in regular season close games, which people might use to make a case for Dallas over San Antonio
-defense becoming more important in the playoffs, which would be a bad thing for Phoenix

We can make this a contest, but we will have to figure out a scoring system first

DSMok1 · Posted: Thu Apr 15, 2010 7:47 am Post subject:

Can you do the same thing with Basketball Geek's efficiency differential ratings? I consider those the best, and since they adjust for both HCA and tempo inherently they are superior to SRS.

EDIT: In fact, because Ryan includes the error associated with each rating, it would probably be better to use a Z-score based estimate of the odds in each game.

In other words: OKC vs. LAL. HCA for LAL: HCA (estimated) of 3.5 (Pts/100 Pos).

Game 1: Normsdist( (LAL-OKC+HCA)/sqrt(OKCerr^2 + LALerr^2) ) = 98%

That doesn't seem right... those errors are too low. Wait! That must be the error of the estimate, not the opponent adjusted standard deviation. duh. Forget this method, then.

**back2newbelf** · Joined: 21 Jun 2005 Posts: 250

DSMok1 · Posted: Thu Apr 15, 2010 9:00 am Post subject:

schtevie · Joined: 18 Apr 2005 Posts: 405

I should think that these simulation results are substantively incorrect if they are based upon the entire 2009-10 season. Just to take two examples, the Celtics started off 23-5, but this is not how they finished. Also, the beginning of the year saw the Shaq etc. integration problems in Cleveland. Why not try running simulations based on the back half of the season as a comparison. That should be more suggestive.

Better still, though it would be difficult to come up with a simple rule, would be to model anticipated lineup usage. Coaches tend to tighten these up and this surely influences outcomes on the margin.

DSMok1 · Posted: Thu Apr 15, 2010 9:22 am Post subject:

**back2newbelf** · Joined: 21 Jun 2005 Posts: 250

Ryan J. Parker · Joined: 23 Mar 2007 Posts: 707 Location: Raleigh, NC

I use data from each possession, so it is still important (for me) to adjust for this, even after an 82 game season. Also, I don't have data for every game. Cool

DSMok1, the errors are for the mean estimate, so you won't be able to use those to estimate win probabilities.

Also, I fit a uniform per possession HCA. It would be really nice to fit this as a hierarchical model, but doing the computation required for this multinomial model is tough for me at this point.

This is part of my senior project, so I'll more in depth details will be available soon.
_________________
I am a basketball geek.

DSMok1 · Posted: Thu Apr 15, 2010 10:27 am Post subject:

DSMok1 · Posted: Thu Apr 15, 2010 10:59 am Post subject:

Estimated team ratings based on Statistical Plus/Minus, adjusting for estimated playing time in the playoffs.

In general, I bumped up the players who normally get the most playing time for each team. The basic method was to take all players MPG^1.45 and then sum the team totals to 240. (Bench players who played in quite a few minutes in just a few games, like Sebastian Telfair, had their factor multiplied by GP/82). Of course, I also adjusted based on the injury prognosis for each player.

The results:

Western Conference:
1 LAL 9.13
8 OKC 6.22

4 DEN 6.86
5 UTA 7.97

3 PHX 6.61
6 POR 7.27 (with Roy at half of expected PT, 5.75 if he is out completely, 8.55 if he plays normally)

2 DAL 5.45
7 SAS 8.23 (The big 3 bumped up to 35 minutes a game)

Eastern Conference:
1 CLE 10.85
8 CHI -2.01

4 BOS 5.82
5 MIA 4.61

3 ATL 7.09
6 MIL -0.18

2 ORL 9.02
7 CHA 3.20

Neil Paine · Joined: 13 Oct 2005 Posts: 774 Location: Atlanta, GA

I got similar results when I did this yesterday, except I used "True SPM Skill", which is a predictor of next year's SPM, and then backed out the 2011 age adjustment:

DSMok1 · Posted: Sat Apr 17, 2010 8:01 am Post subject:

DSMok1 · Posted: Sat Apr 17, 2010 8:39 am Post subject:

Okay, using the new SPM regression, and updating for the latest injury reports.

The results:

Western Conference:
1 LAL 8.71
8 OKC 6.11

4 DEN 6.79
5 UTA 7.63

3 PHX 7.09
6 POR 6.02

2 DAL 5.73
7 SAS 7.97 (The big 3 bumped up to 35 minutes a game)

Eastern Conference:
1 CLE 10.38
8 CHI -0.71

4 BOS 5.60
5 MIA 4.61

3 ATL 7.39
6 MIL 0.25

2 ORL 8.93
7 CHA 3.09

DSMok1 · Posted: Sat Apr 17, 2010 11:05 am Post subject:

Okay, here are my playoff calculations, similar to what B2NB did. I actually calculated the outcomes rigorously (looking at the odds of each possible permutation and summing) rather than running a Monte Carlo sim.

These are based on the adjusted team efficiencies in the last post. I applied a home court advantage of 3.7 pts/100 poss, used an average efficiency of 107, and used a pythagorean exponent of 14.

LAL vs OKC
4 to 0 10.4%
4 to 1 23.0%
4 to 2 16.6%
4 to 3 20.7%
3 to 4 9.1%
2 to 4 12.3%
1 to 4 5.1%
0 to 4 2.7%

LAL OKC
70.8% 29.2%

DEN vs UTA
4 to 0 4.4%
4 to 1 13.2%
4 to 2 11.4%
4 to 3 19.0%
3 to 4 13.1%
2 to 4 20.7%
1 to 4 11.3%
0 to 4 6.9%

DEN UTA
48.0% 52.0%

PHO vs POR
4 to 0 7.3%
4 to 1 18.5%
4 to 2 14.6%
4 to 3 20.8%
3 to 4 11.1%
2 to 4 16.1%
1 to 4 7.5%
0 to 4 4.2%

PHO POR
61.1% 38.9%

DAL vs SAS
4 to 0 3.0%
4 to 1 9.8%
4 to 2 9.0%
4 to 3 16.7%
3 to 4 13.8%
2 to 4 23.7%
1 to 4 14.5%
0 to 4 9.6%

DAL SAS
38.4% 61.6%

---------

CLE vs CHI
4 to 0 40.1%
4 to 1 36.8%
4 to 2 13.6%
4 to 3 7.0%
3 to 4 1.0%
2 to 4 1.1%
1 to 4 0.3%
0 to 4 0.1%

CLE CHI
97.5% 2.5%

BOS vs MIA
4 to 0 7.1%
4 to 1 18.2%
4 to 2 14.4%
4 to 3 20.8%
3 to 4 11.2%
2 to 4 16.3%
1 to 4 7.6%
0 to 4 4.3%

BOS MIA
60.6% 39.4%

ATL vs MIL
4 to 0 24.2%
4 to 1 34.2%
4 to 2 17.9%
4 to 3 14.3%
3 to 4 3.5%
2 to 4 4.0%
1 to 4 1.3%
0 to 4 0.6%

ATL MIL
90.6% 9.4%

ORL vs CHA
4 to 0 19.6%
4 to 1 31.7%
4 to 2 18.4%
4 to 3 16.8%
3 to 4 4.8%
2 to 4 5.8%
1 to 4 2.0%
0 to 4 0.9%

ORL CHA
86.5% 13.5%

Subsequent rounds in the next post:

DSMok1 · Posted: Sat Apr 17, 2010 12:01 pm Post subject:

Continued:

Round 2:

LAL vs UTA
4 to 0 7.1%
4 to 1 18.1%
4 to 2 14.4%
4 to 3 20.7%
3 to 4 11.3%
2 to 4 16.4%
1 to 4 7.7%
0 to 4 4.3%

LAL UTA
60.3% 39.7%

PHO vs SAS
4 to 0 4.4%
4 to 1 13.0%
4 to 2 11.3%
4 to 3 19.0%
3 to 4 13.1%
2 to 4 20.9%
1 to 4 11.4%
0 to 4 7.0%

PHO SAS
47.7% 52.3%

CLE vs BOS
4 to 0 16.2%
4 to 1 29.2%
4 to 2 18.2%
4 to 3 18.5%
3 to 4 6.1%
2 to 4 7.6%
1 to 4 2.8%
0 to 4 1.3%

CLE BOS
82.2% 17.8%

ORL vs ATL
4 to 0 8.2%
4 to 1 19.9%
4 to 2 15.3%
4 to 3 20.9%
3 to 4 10.5%
2 to 4 14.9%
1 to 4 6.7%
0 to 4 3.6%

ORL ATL
64.2% 35.8%

Semifinals:

LAL vs SAS
4 to 0 6.5%
4 to 1 17.2%
4 to 2 13.8%
4 to 3 20.5%
3 to 4 11.7%
2 to 4 17.2%
1 to 4 8.3%
0 to 4 4.7%

LAL SAS
58.0% 42.0%

CLE vs ORL
4 to 0 8.0%
4 to 1 19.6%
4 to 2 15.1%
4 to 3 20.9%
3 to 4 10.7%
2 to 4 15.1%
1 to 4 6.8%
0 to 4 3.7%

CLE ORL
63.6% 36.4%

Finals:
CLE vs LAL
4 to 0 8.7%
4 to 1 13.4%
4 to 2 22.8%
4 to 3 20.9%
3 to 4 10.2%
2 to 4 9.8%
1 to 4 10.8%
0 to 4 3.4%

CLE LAL
65.9% 34.1%