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Michigan State Basketball Odds Update: I Feel Like Dancing

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What seemed like an impossible task just a few weeks ago is now a virtual certainty. Michigan State is headed to the NCAA Tournament. While we wait for the postseason to begin, let’s run the final numbers on the regular season and turn our eye on the Big Ten Tournament.

Michigan v Michigan State Photo by Gregory Shamus/Getty Images

In retrospect, we really should have seen this coming.

Well, maybe that is a stretch. After all, the 2020-21 Michigan Sate Spartans were just 4-9 on Feb 17. Long-time Spartans fans had seen Tom Izzo-coached teams weather adversity in the first months of the season only to surge to greatness in closing weeks of the season. But this year, with this team, the hole seemed too deep.

There were so many reason to doubt this team. The players and staff suffered through COVID outbreaks, shooting slumps, and maddening inconsistency, and all of these things just happen to hit in a year when the Big Ten is the strongest conference of the entire Kenpom era. It also did not help that the Spartans just graduated one of the best point guards that has ever worn the Green and White in Cassius Winston. Tom Izzo is one of the greatest coaches of all time, but even he seemed to have no answers.

But then came the win at Indiana, followed by the wins over Illinois and Ohio State, and Spartans fans dared to hope. The Spartans faltered at Maryland, but closed out at the Hoosier at home to put themselves right at the doorstep of a very improbable bid to the NCAA Tournament. Finally, MSU was able earn a split with the Big Ten Champion Michigan Wolverines to drive the record to 9-11 in Big Ten play.

With three top-10 wins over less than a two-week span, Tom Izzo has done it. Again. At some point in the future, MSU will miss an NCAA Tournament. It will not be in 2021. I don’t know about you, but I feel like dancing.

For those listening closely to the words of Coach Izzo in the postgame press conferences, it is very clear that this team has struggled mightily with the extraordinary circumstances of this season. There is no doubt in my mind that there are stories that have gone untold about the things that have happened in Breslin Center behind closed doors. You can just see it on Coach Izzo’s face. Someday we might hear more about what really happened. Or, we may not.

For this reason, I do think that it is fair to say that, despite the record, this may be the best coaching job of Coach Izzo’s career. What I can also say for me personally is that I have never been so proud of a team that finished under .500 in conference play than I am of the 2020-21 Spartans. They needed a virtual miracle just to get into the NCAA Tournament bubble conservation. Over the past two weeks, they achieved that and more. And, they aren’t finished just yet.

Final Big Ten Standings

As the Big Ten regular season is now complete, there are no more expected wins or championship odds to calculate. Below is the final Big Ten enhanced standings.

Table 1: Final Big Ten enhanced standings

From the enhanced Big Ten standings, the main thing to point out is that not only did Illinois beat the Wolverines badly head-to-head, the Fighting Illini also won two more Big Ten games, but officially finished in second place due to win percentage. It should come as no surprise that Illinois is a bit salty. Do the Illini have a legitimate gripe?

The problem is that Michigan played only 17 of the originally scheduled 20 conference games, while every other Big Ten team played at least 19. While Michigan would have been clearly favored in each of the cancelled games, two of those games were on the road, and as the Wolverines found out on Sunday, no road game can be taken for granted.

Based on the final Kenpom efficiencies, it is possible to project the spreads and odds for the Wolverines in each of the three cancelled games:

  • Michigan (-7) at Penn State (76 percent odds for Michigan to win)
  • Indiana at Michigan (-11.5, 87 percent odds)
  • Michigan at Northwestern (-11, 86 percent odds)

If we multiple those three odds together, we can say that the Wolverines only had about a 57 percent chance to sweep those three games. In other words, there was a 43 percent chance that the Wolverines would had lost a game, and that subsequently, Illinois would have earned at least a share of the Big Ten title.

If I were an Illini fan, those numbers would have me pretty upset as well. If Illinois were to beat Michigan again in the Big Ten Tournament, or if the Wolverines bow out early, this will only add fuel to the fire and bolster the Illini’s claim to the title.

For much of the season, Michigan was not only at the top of the standings, but they were also at the top in the category of “luck.” As Figure 1 below indicates, the Wolverines’ luck perhaps ran out in East Lansing.

Figure 1: Calculated final “luck” metric (actual wins minus expected wins)

In the final calculation, the Wolverines were the fourth most lucky team, behind Illinois, Purdue, and Michigan State. The Spartans were close to the bottom of the conference in luck until the final two weeks of the season, but the Green and White ended up as the luckiest team in the conference, based on this metric.

So, was MSU simply lucky to have won three games over top-five opponents in the last two weeks? Honestly, some luck and/or grit was certainly involved, but the odds of the Spartans beating Illinois, Ohio State, and Michigan based on the projected spreads is only one percent. Therefore, a more likely hypothesis is that the Spartans are simply a better team right now than their current Kenpom efficiency (which is an average over the entire season) would suggest. I believe that our eye balls are telling us the same thing.

In fact, in order to adjust the Spartans’ luck back to zero, MSU’s adjusted efficiency margin would have to be increased to almost +20.00, up from the current value of +15.50. This would increase MSU’s Kenpom ranking into the top 30 instead of the mid-50s where it is currently located. That feels about right, and if anything, might be a bit conservative on any given night.

Final Big Ten Strength of Schedule

It is also a good time to revisit the final strengths of schedule for the Big Ten, which are shown below in Figure 2.

Figure 2: Final Big Ten strengths of schedule assuming as average power five team played the schedule of each Big Ten team

In the final analysis, the two best teams in the conference, Illinois and Michigan, grade out to have the easiest overall conference schedules, even when Michigan’s three “easy” un-played games are removed from the equation. The Spartans finished with the third-hardest schedule in the conference, trailing only Minnesota and Northwestern.

A simple look at the schedule confirms this calculation. After all, Michigan and Illinois only played each other once and both teams also only played the third-ranked Big Ten team once (who is Iowa, at least according to Kenpom). But, all three of those teams also have the distinct advantage of not having to play themselves.

In my preseason analysis of the Big Ten schedule, I attempted to adjust for this factor by rerunning the calculation in a scenario where the strength of an average Big Ten team (in this case, Indiana) is artificially adjusted such that the Hoosiers are a good as the team in question.

In other words, when analyzing Michigan’s schedule, Indiana is “replaced” by a team as good as Michigan. Similarly, when analyzing Nebraska, Indiana is replaced by a team as “good” as the Cornhuskers. The final results of this calculation are shown below in Figure 3.

Figure 3: Adjusted final Big Ten strengths of schedule

As we can see, even with this correction, Michigan and Illinois still had the two easiest schedules in the conference, while teams like Michigan State, Minnesota, and Northwestern still have the most difficult schedules. The only significant difference is that Purdue and Iowa’s strengths of schedule difficulties are closer to the average after this adjustment.

Simulating the Big Ten Tournament

Now that the regular season is finally in the rear view mirror, it is time to officially turn our focus to the postseason, starting with the Big Ten Tournament. The bracket is now set and it is shown below:

The Spartans earned the No. 9 seed and will face No. 8 seed Maryland on Thursday at 11:30 a.m. EST. If the Spartans win, they will once against face Michigan in the quarterfinal round on Friday, also at 11:30 a.m. If the Spartans were to beat the Wolverines again, they would mostly likely face either Purdue or Ohio State on Saturday in the semifinals.

Throughout the regular season, I have been simulating the results of the Big Ten Tournament using the projected seeds. Now, it is finally time to present the results of the simulation using the actual seeds and final Kenpom efficiencies to estimate point spreads and win probabilities. The results are shown below in Table 2.

Table 2: Big Ten Tournament odds from a 50,000 cycle Monte Carlo simulation and in comparison to the Vegas odds.

Note that in the final column I have included the posted Vegas odds for each team to claim the postseason crown. As you can see, my simulated odds agree fairly closely with the Vegas odds.

In general, Vegas odds are a bit better than my simulated odds for two reasons. First, the Vegas odds do not sum to 100 percent and second, Vegas is less likely to make money if the true odds are better than the odds that they will have to pay out. As a first pass, a wager on one of the top three teams looks reasonable, while the odds for a wager on any of the other teams looks like a poor investment.

As for the Spartans, the table suggests that Michigan State only has a 40 percent chance to beat Maryland, a five percent chance to beat Michigan and advance to the semifinals, and only a 1-in-350 chance to win the Big Ten Tournament.

These numbers are accurate if we assume that MSU’s current Kenpom efficiency is a true representation of how good MSU is right now. In most years, this is likely a pretty good assumption. However, as we all know, 2021 is far from an ordinary year.

Based on the odds set by Vegas, the folks in the dessert that make money on knowing these probabilities clearly think that Michigan State has better odds than 1-in-350. In fact, MSU has the seventh-best odds in the conference at 25-to-1.

As a final thought experiment, I reran the Big Ten Tournament simulation using different assumed Kenpom efficiency margins for the Spartans to see how the odds might improve. I varied the efficiency margin from 15.5, where MSU is now, up to 32.5, which is slightly better than Michigan’s current efficiency margin. The results of this set of simulations is shown below in Figure 4.

Figure 4: MSU’s odds to win the Big Ten Tournament if the Spartans’ true efficiency is similar to other Big Ten teams

The figure suggests that even if Michigan State is in reality a No. 1 seed caliber team, the odds of winning the Big Ten Tournament are not great. If MSU’s efficiency is actually close to that of a team like Ohio State, the Spartans’ odds would only go up to around six percent. If the Spartans were as good as Illinois (or Iowa), the odds are just above 12 percent. If MSU is, in reality, better than Michigan, the odds are still under 20 percent.

This results tells us two things. First, winning the conference tournament in a year when the Big Ten is this strong is really, really hard. Second, getting the double bye and starting the tournament is a significant advantage.

One has to look no farther than the case of Michigan, whose odds are just over 30 percent. If I artificially inflate the Spartans’ efficiency to be similar to that of the Wolverines, MSU’s odds are roughly half, due to the harder draw and need to play an extra game. Once again, as Michigan taught us this year, the odds of losing are way lower if you simply don’t have to play the game.

That is all for today. Until next time, enjoy, and Go State, Beat the Terrapins!