True Hoop 2011 Third Round

As the playoffs go on the picks necessarily get harder, and the odds get worse. The Bulls-Heat series is a prime example. Under the ratings currently posted, the Bulls win just over 50% of the time, and the most likely outcome is Miami in 6. In order to nail this pick down though, I started playing with the ratings a little bit. Turns out that for the NBA they are overly generous to teams that win low scoring contests (read: The Bulls), so I tweaked things a little bit. Now the power ratings match up a little closer to the points ratings (almost exactly for Bulls Heat it turns out) and favor the Heat to win the series 53.1% of the time. On the other side of things, no matter the results of Game 7 Dallas will be favored to win in 7 games (although by just .05% over 5 games against the Griz). So for round 3 I have:

Miami in 6

Dallas in 7

Neither of these look to catch me up much on the top half of TrueHoop guys, but if OkCity wins tomorrow I'll pass David Berri despite picking fewer winners than him (master of series length!). And this point, I'm rooting against myself anyways, GO BULLS!

True Hoop 2011 Second Round

After the first round of the NBA playoffs I've accumulated 29 total points which would put me in 5th in the TrueHoop Stat Geek Smackdown. It's not as good of a start as last year, but I'm still in the game. Here are my picks for the second round (full odds and analysis will come sometime tomorrow).

Chicago over Atlanta in 5

Miami over Boston in 5

Oklahoma City over Memphis in 7

Los Angeles over Dallas in 7

It's pretty bland, going with all favorites, but I'm hoping to gain a couple points in series length. 2.83 expected series wins plus .97 expected series length picks means I should hope for about 16 points this round. A little better would be a nice boost too.

Picking Playoff Series Length

People who are good with numbers may have noticed that I picked an unreasonably large number of first round series' to be 5 games long. In fact, people who aren't good with numbers probably noticed it also because I picked 7 out of 8 to be the same length. It turns out however, that for a series with a clear favorite, that's the most likely out come. In fact, there are easy rules to follow.

*This all assumes that home teams win 60% of the time with equal skill. This also does not apply to the finals which have a different format (2-3-2).

When to...

Pick the home team in four

As I noted last year, sweeps are surprisingly unlikely. It's even more unlikely that a sweep is the most likely outcome, in fact there is no case where that could happen in this year's playoffs. Pick a sweep only when the home team is 3.67 or more times better than the away team, or has at least a 96.2% chance of winning.

Pick the home team in five

This is a much more common choice, especially with a lopsided first round series. Pick this when the home team is between 1.27 and 3.67 times better, or has between a 64.5% and 96.2% chance of winning.

Pick the home team in six

Never! The sixth game is on the road, so any team likely to win it probably would've already won in 5.

Pick the home team in seven

While rarer, when two teams are especially close the most likely outcome is often the home team in 7 games. Pick it when the home team is between .97 and 1.27 times better, or has between 51.2% and 64.5% odds of winning.

What?!? 51.2%? What if it's 51.0%, do you pick the home team in eight or something??

Turns out, that when the home team is slightly favored the most likely outcome is that the away team wins in 6 games, even though it's smarter to pick the other team to win. How do you compensate for this? It depends on what value is assigned to each. Using TrueHoop's 5 points for series winner and 2 points for correct number of games the boundary is set at .944 times better, or when the home team has a 50.1% chance of winning.

Pick the away team in seven

Don't do it! If they can win in seven, they're more likely to win in game 6 when they're at home.

Pick the away team in six

If you're going to pick the away team to win, unless for some super weird reason the away team is waaaaaaay better. Accordingly, pick the away team in six when it's 1.04 to 2.38 times better, or has between a 48.8% and 85.8% chance of winning.

Pick the away team in five

There's only a brief range where this is the right choice, but it still exists. If the away team is 2.38 to 2.83 times better, implying between 85.8% and 90.3% chance of winning, then pick the away team in five.

Pick the away team in four

If the away team is 2.83 or more times better, meaning they'll win at least 90.3% of the time, then pick them to sweep. This has probably never happened, and probably never will.

Summary (for lazy readers):

If you think the home team will win pick them in 5 games, unless if you think it's close than go with 7 games. If you think the away team will win, pick them in 6 games pretty much no matter what. Importantly, while it's often tempting it's never smart to pick the home team in 6 or the away team in seven. There will of course be sweeps this year, and home teams that win in six, but from a purely mathematical perspective, that's not a smart pick going in.

True Hoop First Round

TrueHoop once again is running their true hoop challenge, and well I'm not officially a participant (someday...) I'm still going to put my predictions out there (which were done before today, just posted late):

Bulls over Pacers in 5

Magic over Hawks in 5

Celtics over Knicks in 5

Miami over 76ers in 5

Spurs over Grizzlies in 5

Nuggets over Thunder in 6

Mavs over Blazers in 5

Lakers over Hornets in 5

Yes it's bland, but that's what all the math says. None of the series' are close enough to be expected to go to 7 (although it's probably that at least one will), and only the Nuggets are set for an upset.

Also of note, my first three (okay, really two) articles outside of Kobe, Tell Me How My Stats Taste! The TeamRankings one has good math, and the ESPN one has good comments.

Second Round Predictions

Running the second round games, with the same home court advantage, I end up with the following:
Cle-Bos: Cleveland in 5
Orl-Atl: Orlando in 5
Phx-SAS: San Antonio in 6
LAL-Utah: Utah in 6
You may or may not point out that Cleveland, Utah, and even kind of San Antonio have me in trouble. I just say that it's proof that I don't just make these up, and it really is the math (if you want actual proof I guess I can put it up, but that's a lot of math).
As a non-math biased basketball fan, I personally would've said Cavs in 5, Magic in 5, Lakers in 6, and Spurs in 7. I think more so than any other team, my Power Rankings underestimate the Lakers because it's an average of all games, while the Lakers have the skill to turn it up another level that we haven't seen all season (this may be going on with the Celtics also).
Note: For those of you questioning the Lakers over Utah pick, the computer only has Utah winning 50.2% of the time. So I'm not super optimistic about a comeback.

First Round Predictions.

Running the numbers with a home court advantage of .6 (among equal teams home team wins 60% of the time) these were the first round predictions of my Power Rankings:
Cle-Chi: Cleveland in 5
Orl-Cha: Orlando in 5
Atl-Mil: Atlanta in 5
Bos-Mia: Boston in 7
LAL-OkC: LA in 7
Dal-SAS: SA in 6
Phx-Por: Suns in 7
Den-Utah: Utah in 6
That's right, all 8 series winners were right! Using the TrueHoop Stat Geek scoring system (5 points for winners, 2 for the right number of games) that's 46 points in the first round, which would put me in first place. What's that Hollinger? You say you're looking for an intern?
If so, please ignore my second round predictions. You'll see why in the next post.

Unlikely Sweeps

As the playoffs progress into the second round, it may seem surprising that there's only been one sweep so far. It turns out though that even a heavy favorite is more likely to win in five playoff games then to sweep. For example, the most uneven first round series was the Cavs Bulls series. Based off of the power rankings (and a slight home court advantage) the Cavs were supposed to sweep 31.1% of the time (0.32% of the time for the Bulls). 35.5% of the time though they would win in 5 games. So despite all 7 True Hoop stat geeks predicting a sweep, a 5 games series was most likely. It was also what happened.

For the numbers intensive, what sort of power rankings lead to a sweep? Team A must be at least 3.67 times better than Team B for a sweep to be more likely than a four game series. That's a bigger difference than the difference between Orlando, the highest rated team, and Chicago, the lowest rated playoff team. That doesn't mean there won't be any sweeps this playoff, just that I won't be predicting any.