Michigan State Basketball Odds Update: Happy New Year!

Happy New Year, Spartan fans! First off, I just wanted to congratulate Coach Mel Tucker and the Michigan Sate University Football team on the exciting, come-from-behind win over Pittsburgh in the Peach Bowl. 

Now that the football season is in the books, it is time to shift focus to basketball. A month ago, I provided an initial analysis of the Big Ten basketball season based on a simulation that used Kenpom efficiency data as the primary input. I am able to use this data to perform a full simulation of the Big Ten season as well as the Big Ten Tournament.

As conference play is set to resume, it is time to check back on the data to see what has changed and where MSU and the rest of the conference now stands.

Enhanced Big Ten Standings and Updated Odds

Figure 1 below visualizes the current Kenpom adjusted efficiency margins for the 14 teams in the Big Ten. As a very brief reminder, efficiency margins represent the point differential that each team would be expected to have against an average Division 1 team if a game were 100 possessions long. These numbers can be used to project point spreads and victory probabilities for any potential basketball match-up.

Figure 1: Kenpon adjusted efficiency margins for the Big Ten as of Jan. 1, 2022.

The Kenpom data still suggests that Purdue is the best team in the conference, but the Big Ten also contains seven other teams ranked in the current top 30 of adjusted efficiency margin: Illinois, Ohio State, Michigan State, Michigan, Iowa, and Indiana.

In addition, in Table 1 below I present the current enhanced Big Ten standings as of Jan 1. The table contains the current Kenpom efficiency margins and rank for each team as well as the current win and loss total, the "plus / minus," the number of expected wins to data, and each team's "luck."

Table 1: Enhanced Big Ten standings as of Jan. 1, 2022.

The "plus / minus" metric gives each team a point for a road win and subtracts a point for a home loss. This metric is useful to compare teams during the season when the schedules are imbalanced. "Luck" is defined as the difference in actual wins and expected win, where the expected wins are the sum of the victory probabilities for all the games that have already been played.

It is still early in the season to read too much into this data, but it is notable that only three teams were able to win two of the December conference games: Illinois, Ohio State, and Michigan State. 

Table 2 below gives the updated win distribution matrix based on a 100,000 cycle Monte Carlo simulation using Kenpom efficiency margins as the input. Table 2 also shows the changes in the Kenpom ranking and expected wins since the beginning of Big Ten play in early December.

Table 2: Updated Big Ten expected wins and win distribution matrix.

Purdue's expected win total took a hit following the Boilermakers upset loss to the Scarlet Knights of Rutgers, but Purdue still has almost a full game lead on the rest of the pack. This pack is led by a group of three teams (Ohio State, Illinois, and Michigan State) who have expected wins totals between 13 and 14. All three team's expected win totals moved up by between one and two games in the month of December.

Michigan State is now projected to finished conference play with 13 wins. That said, there is still a 15 percent chance that the Spartans can get to at least 16 wins and a 27 percent chance that the win total exceeds 15.

As for other teams that saw a significant change in the number of expected wins over the last month, Minnesota (+2.01) appears to be on the rise, as does Northwestern (+0.91). Teams that lost ground in December include Nebraska (-2.11), Maryland (-1.18), Iowa (-1.00), Michigan (-0.95), and Wisconsin (-0.82).

As for the odds to win or share the Big Ten title, Table 2 shows that summary.

Table 3: Updated odds to win or share the Big Ten title and the win distributions for those winning teams.

While the Boilermakers took a clear hit in expected wins, Purdue still has the best odds to hang a regular season banner at just over 40 percent (down 16 percent from early December). The next most likely challengers include Ohio State (28 percent), Illinois (24 percent), and Michigan State (18 percent, which is up eight percent). 

The next five teams (Michigan, Iowa, Indiana, Northwestern, and Wisconsin) all project to have odds between two and favors to win the Big Ten regular season title. The odds for the remaining five Big Ten teams are currently less than 0.3 percent.

The win distribution in Table 3 suggests that the eventual Big Ten champion will most likely have a record of 16-4 (31 percent), but a final record of 17-3 (26 percent) or 15-5 (20 percent) are still both plausible.

Big Ten Tournament and Strengths of Schedule

Table 4 below summarizes the projected seeds for the eventual Big Ten Tournament.

Table 4: Big Ten Tournament seeding odds as of Jan. 1, 2022. The numbers in parentheses are the changes since early December.

Here I calculate the projected seeds for each team based on the weighed probabilities of all 100,000 simulation results as well as the seeds in the situation where the projected favorite wins all remaining Big Ten games.

In both cases, the top four seeds and the coveted double byes would go to Purdue, Ohio State, Illinois, and Michigan State. The current numbers give the Spartans about a 57 percent chance to secure a top four seed. 

As for the eventual winner of the Big Ten Tournament, those odds are shown below in Table 5.

Table 5: Odds for each Big Ten team to advance past each round of the Big Ten Tournament.

As a general rule, these odds will track with the overall Kenpom adjusted efficiency margins. Purdue still has the best overall odds (32 percent). Michigan State's current odds to hang a tournament title banner are 11 percent.

Figure 2 below gives the updated strength of schedule data for the Big Ten. The left panel of Figure 2 gives the updated calculation for each team's entire schedule. The right panel summarizes the strength of each team's remaining conference schedule. In both cases the numbers represent the winning percentage that an average power five team (such as Iowa) would be expected to have with each team's schedule.

Figure 2: Updated Big Ten strengths of schedule both overall (left) and of the remaining conference games (right)

At the close of the non-conference season, Michigan State full schedule still grades out with the third easiest Big Ten schedule behind only Ohio State and Indiana (see the left panel of Figure 2). That said, the Spartans also opened with two fairly light conference opponents in December. As a result, MSU's remaining conference schedule is actually the sixth hardest (right panel).

Here I would also like to make a brief comment about the Michigan Wolverines. Despite the fact that Michigan opened the season with a lofty top five ranking, the Maize and Blue have struggled and are off to a 7-5 record with no Kenpon top 40 wins. As Table 2 above shows, Michigan is only expected to win a total of 11 conference games with brings their projected record to just 17-13. 

This record would place the Wolverine's squarely on the NCAA Tournament bubble and very likely on the wrong side of it, considering the lack of quality wins. Furthermore, the numbers in Table 3 suggest that there is a 43 percent chance that Michigan posts only a 10-10 conference record, or worse. This would almost certainly spell doom for the Wolverine's March Madness dreams. 

Figure 2 helps to explain why things look so bleak. Michigan has the most difficult remaining conference schedule.

MSU's Kenpom Trajectory and Remaining Schedule

For the first time in the 2021-22 season, I would like to introduce another visual that I find useful. Figure 3 below is a plot of Kenpom adjusted defensive efficiency (points allowed per 100 possessions) on the y-axis versus the Kenpom adjusted offensive efficiency (points scored per 100 possessions) on the x-axis. The adjusted efficiency margins form diagonal lines on the plot, as this is defined as the difference between the offensive and defensive efficiencies.

Figure 3: Kenpom efficiency scatter plot as of Jan. 1, 2022.

Figure 3 contains efficiency data for four separate sets of teams, both past and present. The small blue diamonds show the pre-tournament data for the last 19 teams to win the National Title. The position of these 19 teams define an area of the plot shaded in light blue which I call the "championship zone." As a general rule, history tells us that in order to be a serious contender to cut down the nets in March, a team's efficiency profile must fall within this blue are of the figure.

The red triangles denote the teams in 2022 that current have efficiency numbers that fall into the championship zone. There are currently 17 teams that fall into this category, including Purdue, Illinois, Ohio State, Michigan State, and Michigan.

The large green circles represent the profiles of past MSU teams, and while the smaller green circles and line represent the efficiency evolution of the current Spartan team over time since the beginning of the season, according to Kenpom data. 

The error bars and light green oval represents the historical uncertainty (i.e. one standard deviation) of the Kenpom efficiency at this point in the season. This oval is currently rather large, but it will shrink as selection Sunday approaches.

At the beginning of the season, the Spartans graded out as a team that had a good enough defense to enter the championship zone, but the offense was a bit lacking. However, over the past few weeks, the 2022 MSU team has improved in Kenpom adjusted offensive efficiency such that the team now resides on the edge of the championship zone.

Right now, the 2022 MSU team statistically most resembles Tom Izzo's 2007 team that advanced to the round of 32. That said, several teams who faired much better that the 2007 team, including the 2010 and 2009 Final Four teams both fall into the green oval. If the Spartan can hold several on defense and continue to improve on offense, they will continue to look more and more like a legitimate contender for at least the Final Four.

Finally, Figure 4 below summarizes the remainder of MSU's schedule, including the projected point spreads and victory probabilities that are derived from Kenpom efficiencies.

Figure 4: Odds for MSU to win the remaining Big Ten games, based on Kenpom efficiency margins.

As of Jan. 1st, the Spartans are projected to be favored in 13 of the remaining 18 conference games. Three of the games where MSU projects to be an underdog occur in the final week and a half of the season when MSU plays at Iowa, versus Purdue, and at Ohio State. Prior to that, the Spartans project to be underdogs at Michigan and at Illinois. That said, MSU is also only a slight favorite in multiple games this year.  

As I mentioned a month ago, the front end of the Spartan's schedule is lighter. The next five games, including the road game to Ann Arbor, all seem very winnable. If MSU can get to 16-2 (7-0) before the bye week in late January and prior to the road trip to Madison, the Spartans will very much be in the mix to challenge for at least a share of the Big Ten title.

But, that all starts with this afternoon's contest at Northwestern. So with that I will simply say Go State, beat the Wildcats!