RPI: Why Cupcakes Matter, Part I

On the MUScoop.com website, I've had a running discussion going as the schedule developed. One of the questions that came up was how much of an impact playing tougher cupcakes had as opposed to some of the weaker teams we've seen in years past. In order to do this, first it's important to understand how the RPI works. The RPI that matters is the one calculated going into Selection Sunday, so I include all regular season games as well as conference tournaments. When analyzing a team's RPI, there are three factors involved:

25% - Their weighted record. To calculate this, you need to break down the team's record for home, neutral, and road games. For example, Marquette was 15-1 at home, 4-1 on neutral courts, and 6-5 on the road. Home wins are weighted by a multiple of 0.6 (0.6 x 15 = 9) and road wins are weighted by a multiple of 1.4 (1.4 x 6 = 8.4), while home losses are weighted by a multiple of 1.4 (1.4 x 1 = 1.4) and road losses are weighted by a multiple of 0.6 (0.6 x 5 = 3). That gives us the following formulas for Marquette:

Wins: (0.6 x 15) + (1.0 x 4) + (1.4 x 6) = 21.4
Losses: (1.4 x 1) + (1.0 x 1) + (0.6 x 5) = 5.4

So Marquette's weighted record was 21.4 - 5.4, a winning percentage of 0.7985.

50% -  Their opponents' record. This does NOT use the weighted formula. It also ignores the game against the team being calculated. The record of all of Marquette's opponents combined, discounting postseason tournaments and games against Marquette, was 592-394, a winning percentage of 0.6004.

25% - Their opponents' opponents' record. This also does not include the weighted formula, simply the record for every team the teams you played played. The combined winning percentage of all of those teams for Marquette was 0.5327.

In order to now determine Marquette's RPI rank (and thus value as an opponent), it is approximately as follows:

(0.7985 + 0.6004 + 0.6004 + 0.5327) / 4 = 0.6330.

This number is then compared against all the other teams in the country to determine the RPI ranking. Last year, this ranking was good enough for 8th in the country. In the next two parts of this, I will be looking at what the difference is when Marquette plays higher-quality cupcakes as opposed to lower-quality cupcakes, followed by a look at what benefit there is to playing road games against mid-major teams like Green Bay and Milwaukee.