Big Ten Hoops Odds Update: Happy New Year

Happy New Year, Spartan basketball fans. Hopefully everyone enjoyed the holiday season and is rested and ready for the rest of the Big Ten basketball season. 

Since we last checked in on the odds for the Michigan State Spartans to claim a Big Ten title in late December, the Green and White have resolutely posted a perfect 5-0 record. The Spartans even delivered a late Christmas present to fans in the form of a home win this Saturday against their rivals from Ann Arbor. In this regard, it was a fairly happy holiday.

Now that the non-conference schedule is complete and two more Big Ten games are in the books, it is time to take a look at the numbers to see where Michigan State stands in the Big Ten race.

Updated Big Ten Standing, Wins, and Odds

With 22% of the Big Ten season complete, it is time to introduce one additional data table that I like to use. Table 1 below is what I refer to as the enhanced Big Ten standings. It includes the current Big Ten record of each team in addition to three other pieces of data. 

First, it contains the current Kenpom rankings and adjusted efficiency margins (AdjEM) for each team as of the morning of Dec. 9. Second, it contains the "plus/minus" for each team. The value is equal to the number of road wins minus the number of homes losses. 

Third, Table 1 lists the current "luck" for each Big Ten team. I define luck as the difference between the actual number of wins and the expected number of wins so far, based on the retroactive spreads derived from the Kenpom adjusted efficiencies of each team.

Table 1: Enhanced Big Ten standings as of Jan. 9, 2023.

Purdue is currently at the head of the class with a half-game lead, a 4-1 record, and the best Kenpom ranking in the conference (No. 6 nationally). Three of Purdue's wins have come on the road and the lone loss occurred at home which gives the Boilermakers a Big Ten-best plus/minus of +2.

Michigan State is currently in a four-way tie for second place along with Michigan, Wisconsin, and Northwestern at 3-1. The good news is that the Spartans are the highest Kenpom-ranked team in that group at No. 43. However, the other three teams are all +1 while the Spartans are zero in the plus/minus metric.

Table 2 below shows the updated Big Ten wins matrix, based on a 100,000-cycle Monte Carlo simulation of the rest of conference season.

Table 2: Updated Big Ten expected wins and win distribution matrix as of Jan. 9, 2023.

As expected, Purdue is still at the top of the chart with an expected win total of 15.4 wins. However, unlike Table 1, the Spartans are not right below Purdue. The two teams with the next best expected win totals are Rutgers (12.7) and Ohio State (12.3). The Spartans currently have just the eighth best expected win total at 10.15, which is an improvement of over one win since early December.

That said, Table 2 also demonstrates that the Big Ten race is still wide open, especially in the middle. The teams ranked No. 4 to No. 12 are separated by a little over a game-and-a-half of expected wins (10.6 for Wisconsin down to 9.05 for Penn State).

In other words, Purdue is the favorite, Rutgers and Ohio are the dark horses, Nebraska and Minnesota are out of it, and the rest of the conference one can throw into a blender.

This concept is also captured by the updated Big Ten Championship odds matrix shown below in Table 3. 

Table 3: Updated odds to win or share the Big Ten title and the win distributions for those winning teams as of Jan. 09, 2023.

Purdue currently has such a large lead in expected wins (close to three games over Rutgers) that the Boilermakers' Big Ten odds are up to 76%. There is over a 50/50 chance that Purdue wins (or shares) the title with a 16-4 record or better. The simulation also suggests that there is an 81% chance that only one team wins the regular season title this year.

Rutgers and Ohio State have a 15% and a 12.5% chance at the title, respectively. The teams ranked No. 4 to No. 12 have between a 3.8% and 0.6% chance with Michigan State's current title odds at just 2.8%.

Strength of Schedule Update

So why are Michigan State's odds so low considering that the Spartans are just a half-a-game behind Purdue in the standings? The answer is two-fold.

First, based on Kenpom adjusted efficiency, the Spartans currently rank just No. 8 in the Big Ten. Second, Michigan State continues to grade out with one of the more difficult schedules in the conference.

Figure 1 below is the updated strength of schedule calculation for each Big Ten team's remaining slate.

Figure 1: Updated Big Ten strengths of schedule for the remaining conference games as of Jan. 9, 2023.

Michigan State has the toughest remaining conference schedule, and it is not particularly close. Indiana's remaining schedule ranks No. 12 in the Big Ten and it is over a half game easier. 

Rutgers has the easiest remaining Big Ten schedule, which goes a long way towards understanding why the Scarlet Knights have the second best Big Ten odds. The Scarlet Knights' remaining schedule is a full win/game easier than Michigan State's remaining schedule.

For reference, Figure 2 below shows the overall strength of schedule data for each team, including the raw calculations and the corrected value (which attempts to adjust for the benefit or penalty that each team gets for not having the chance to play themselves). 

Figure 2: Updated Big Ten overall strengths of schedule using the raw values (left) and the corrected values (right) which accounts for the benefit (or penalty) for a team to not need to play themselves.

Big Ten Tournament Odds

If the season ended today, that would be weird, because there are still 109 Big Ten conference games left. That said, we can accurately project the odds that each team will earn each possible seed in the Big Ten Tournament using the magic of simulation.

Table 3 below provides these odds.

Table 3: Big Ten Tournament seeding odds as of Jan. 9, 2023. The numbers in parentheses are the changes since the previous update in early December.

As expected, these data track closely with the odds shown above. Purdue, Rutgers, and Ohio State currently project to most likely capture the top three seeds. After that, however, things get messy. 

Michigan State has the best odds of earning the No. 8 seed as the data stands today. However, if all of the teams that current project as favorites were to win all 109 remaining conference games, Michigan State would drop to the No. 11 seed. 

Other teams show similarly strange trends. Michigan projects as the No. 5 seed, but would drop to the No. 12 seed if all of the favorites were to win. By contrast, Indiana currently projects to earn the No. 9 seed, but the Hoosiers would grab the No. 4 seed if all the favorites were to win.

These unusual trends are due to the very large number of close games and near toss-ups remaining on the Big Ten schedule. There are a lot of potential outcomes for each team. Once again, the middle of the conference is wide open.

Also of note, Michigan State has about a 21% chance to finish with a top four seed and a double bye in the Big Ten Tournament. Unfortunately, the odds are almost identical that the Spartans will finish with a bottom four seeds and be forced to start the Big Ten Tournament on the opening day for the first time in history.

Just for reference, Table 4 below shows the odds for each team to win the Big Ten Tournament.

Table 4: Odds for each Big Ten team to advance past each round of the Big Ten Tournament, as of Jan. 9, 2023

Purdue has the best odds at 34% with Ohio State (16%) and Rutgers (13%) next up. Michigan State's odds currently sit at four percent.

Michigan State Schedule and Outlook

Figure 3 below summarizes the projected point spread and win probabilities of all of Michigan State's remaining conference games. 

Figure 3: Odds for MSU to win the remaining Big Ten games, based on Kenpom efficiency margins.

At a glance, it is easy to see why Michigan State's outlook is so unclear. Of the 16 remaining conference games, a full 10 of those games project to have spread of three points or less. Spreads in this range translate to a 40 to 60% chance of a win.

In five games (both Purdue games and road games at Indiana, Rutgers, and Ohio State) the Spartans project to be a slightly larger underdog. Michigan State is only projected to be larger than a 2.5-point favorite in one more game this year: the home game against Minnesota.

The bottom line is that if Michigan State wants to challenge for a Big Ten title (which I do think is very possible) the Spartans will need to win a lot of toss-up games. Or, they will simply need to start playing better such that the odds for a majority of the remaining game shift up. Both are certainly possible.

But as things stand now, Michigan State only projects to be favored in five of the remaining 16 Big Ten games.

The next five games will be an excellent test to see how good this year's Michigan State team will really be. The Spartans will play at Wisconsin, at Illinois, versus Purdue, versus Rutgers, and at Indiana over a 13-day span.

Michigan State projects to be an underdog in all five games. All five games are absolutely winnable, but they are also all "losable."

Based on the projected spreads, the most likely outcome is for the Spartans to go 2-3 in that stretch. If the Spartans win just two of those games, they are basically on track for a 10-10 Big Ten campaign and a stressful Selection Sunday. 

If Michigan State can win three or four games in that stretch then the Spartans will be positioned for a solid finish in the upper tiers of the conference. Based on Table 2, it will not take much "overachievement" to move from No. 8 to No. 4 in expected wins. 

The schedule eases up a bit in late January. There are a fewer slightly easier games on tap (such as Iowa and Maryland at home) and the games are spaced out a little bit more. But the next few games will be a serious test. Over the next two weeks it will become much clearer if the Spartans are contenders or pretenders.