Tuesday, March 29, 2022

Kyrie Irving's Availability Is More Important to the Brooklyn Nets Than Home Court

Kyrie Irving is now allowed to play home games in Brooklyn due to the expanding of the exemption to NYC's vaccine mandate (visiting players were already allowed to play), so the Brooklyn Nets are now closer to full-strength, with their second best player available for all games. As recently as 4 weeks ago, mayor Eric Adams indicated this wouldn't be the case this season - which resulted in one of the most thought provoking hypotheticals in recent NBA memory:

Are the Brooklyn Nets actually better off without home court advantage in the playoffs, since Kyrie can only play away games?

This is borderline heresy, as generic home court is worth 2.4 points in the NBA. This season may be a down a bit to ~1.6, but for evenly matched teams, 1.6 translates to ~4.5% in win probability per game, which translates to a 60/40 series advantage over 7 games (2.4 points is 65/35 over a series, all else equal).

But Kyrie Irving is that good as to throw this into question, as much as that pains me to say (I'm pretty open about where I went to school).

Using my play-by-play NBA simulator, I can directly answer this by swapping Kyrie in/out of the lineup depending upon whether the game is at home, while also accounting for this season's home court advantage.

Assumptions:

  • All teams are at full health, unless a player is out for the year like Joe Harris or Collin Sexton
  • Kyrie does not play in Brooklyn or Toronto, but plays everywhere else
  • Playoff seeding is set as of my most likely sim outcome going in to Sunday's games (3/27), which was also Kyrie's home debut
    • This puts Brooklyn at the 8 seed (more on the one game play-in for the 7 seed in Toronto later)
  • In all other scenarios, every team below where Brooklyn displaces moves down 1 spot. For example, if they're the 1 seed, Miami moves down to 2, Boston to 3, etc
SeedConferenceTeam
1EastMIA
8EastBKN
4EastPHI
5EastCHI
3EastMIL
6EastCLE
2EastBOS
7EastTOR

I'm just going to simulate the East, since it's overwhelmingly likely (> 80%) they would not have home court in the Finals, even if they were 10 wins better and the 1 seed (Nets projected record is 43-39, the Heat (#1 in the East) are projected to 52-30, Warriors (#3 in the West) are projected to finish 53-29).

I first played Brooklyn vs Philadelphia against each other, which provides a good validation on the calibration of the simulator:
  • Philadelphia at Brooklyn (No Kyrie): 67% Philadelphia, 115.9-108.8 average score
  • Brooklyn (Kyrie) at Philadelphia: 60% Philadelphia, 116.5-110.5 average score
  • Philadelphia at Philadelphia: 53% Philadelphia (Home), 115.2-114 average score
  • Brooklyn (Kyrie) at Brooklyn (No Kyrie): 55% Brooklyn (Kyrie), 111.9-109.7 average score
This validates a few things:
  • Brooklyn is better on the road with Kyrie than at home without him
    • With Kyrie is a larger magnitude than home court with Brooklyn playing itself
    • Brooklyn has a better chance beating Philly on the road with Kyrie than at home without him
  • Home court is roughly reflected (1.2 points for Philly at Philly vs 1.6 theoretical)
I then ran each scenario 1,000 times - not much, but each sim is ~41 games over 7 series (328k total games over 8 scenarios).

Here's how the current playoff seeding projects out:

SeedConferenceTeamRound 2Conf FinalsFinals
1EastMIA43.9%21.2%12.4%
8EastBKN56.1%28.0%14.6%
4EastPHI57.9%30.5%16.7%
5EastCHI42.1%20.4%10.0%
3EastMIL57.4%28.4%14.6%
6EastCLE42.6%20.2%8.9%
2EastBOS60.6%35.3%17.7%
7EastTOR39.4%16.0%5.1%

Even with Kyrie playing only 4 out of 7 possible games in the first round, Brooklyn would be favored over the 1 seed in Miami, and have the 3rd best odds to make it out of the East.

This doesn't tell us anything we didn't already know from the Philadelphia/Brooklyn validation test - so here's how Brooklyn's chances look at each seed line in the East:

Seed1st Round2nd RoundECFR1 Matchup
151.6%22.5%9.7%TOR
251.7%23.9%12.7%CLE
348.6%24.3%12.8%CHI
438.6%22.6%12.1%PHI
540.0%25.1%15.1%PHI
649.0%25.1%13.4%MIL
747.8%25.8%15.3%BOS
856.1%28.0%14.6%MIA

The Brooklyn Nets are better off without home court but with Kyrie, i.e. being a 5 seed or worse. The sweet spot seems to be the 7th or 8th seed, pending the play-in game. They have a ~3% advantage as a lower seed to win the East and reach the Finals. This is roughly 1 to 1.5% better in title odds, which is actually a huge difference, as Daryl Morey's rule of thumb is to go all in with at least a 5% chance to win the title:
“If you’ve got even a five percent chance to win the title — and that group includes a very small number of teams every year — you’ve gotta be focused all on winning the title"
Even a Kyrie delta of 1.5% is almost one third of the way there.

And on that play-in game in Toronto - the wrinkle there is Kyrie wouldn't be allowed to play in either city. With him in Toronto, they would be 61% favorites, and without him on the road, they're 56% favorites. A rather large difference, so Brooklyn should definitely be hoping for Toronto to move up to 6 and out of the play-in... except that they might have a better chance beating Toronto without Kyrie than Cleveland with him (if everyone is healthy).

I then played full strength Brooklyn (with Kyrie) against themselves at home, and the home version wins 51.2% of the time, implying a 1.2% home court advantage (HCA) in Brooklyn. By simulating all possible matchups and holding all else constant, I can also isolate Kyrie's effect:

OppHome (wo Kyrie)Away (wo Kyrie)Away (w Kyrie)Kyrie EffectHCA
MIA46.5%46.2%53.2%7.0%0.3%
BOS44.1%42.7%47.7%5.0%1.4%
MIL45.5%43.0%46.3%3.3%2.5%
PHI33.1%31.8%40.0%8.2%1.3%
CHI51.9%49.4%52.8%3.4%2.5%
CLE51.2%49.3%52.6%3.3%1.9%
TOR60.0%60.8%61.7%0.9%-0.8%
4.4%1.3%

Outside of the 76ers (which the simulator loves, speaking of Daryl Morey), Kyrie on the road brings every game to close to a coin flip or better. Intuitively, he has less of an impact the weaker the opponent, since in all these scenarios the Nets still have arguably the best player in the world in Kevin Durant. Holding HCA constant, Kyrie's average effect is 4.4% - over three times that of home court.

Sunday, March 27, 2022

Final Four per the MDS Model (2022)

Well, the singularity is upon us. Even going in to Saturday's games, it was at less than 50/50 chance of happening. 0.46% chance before the tournament started, compared to the long-run average of 2.66%.

SeedTeamChampionshipChampion
Final Four
2Duke67.43%32.72%
8North Carolina32.57%10.19%
2Villanova45.18%24.64%
1Kansas54.82%32.46%

The Coach K Farewell Tour now has the most likely chance of finishing with a championship. After having 6 more likely winners at the start, and having wanted absolutely no part of this as a fan, it now looks like we're going to have to do this ourselves.

I've picked the champion three times going in to the Final Four since I started this in 2014 (Virginia 2019, Villanova 2016, Villanova 2018). I hope I'm wrong this time.

Friday, March 25, 2022

Elite 8 per the MDS Model (2022)

Well, the singularity keeps getting closer and closer.

SeedTeamElite 8Final FourChampionshipChampion
Sweet 16
1Gonzaga0.00%0.00%0.00%0.00%
4Arkansas100.00%40.83%26.27%10.79%
3Texas Tech0.00%0.00%0.00%0.00%
2Duke100.00%59.17%42.75%21.42%
8North Carolina100.00%76.56%27.66%9.10%
4UCLA0.00%0.00%0.00%0.00%
3Purdue0.00%0.00%0.00%0.00%
15Saint Peter's100.00%23.44%3.31%0.41%
1Arizona0.00%0.00%0.00%0.00%
5Houston100.00%51.53%27.34%16.09%
11Michigan0.00%0.00%0.00%0.00%
2Villanova100.00%48.47%25.01%14.35%
1Kansas100.00%77.27%41.75%25.86%
4Providence0.00%0.00%0.00%0.00%
11Iowa St.0.00%0.00%0.00%0.00%
10Miami (FL)100.00%22.73%5.89%1.98%

Of course I care way more about one side of the bracket than the other.
Kansas has the best odds to win the title (1 in 4), but 1 in 5 for Duke is getting far too high for my comfort.