Under the recent NCAA soccer rules change, there no longer will be overtime games during the regular season. All games tied at the end of regular time will be ties. In addition, for conference tournaments and the NCAA tournament, games tied at the end of regulation will have two 10-minute overtimes followed by kicks from the mark if still tied. Thus no more games decided by "golden goal."
How Many Games Should We Now Expect to End as Ties?
Since 2007, 10.8% of Division I women’s soccer regular season games have ended in ties. This includes, as ties, conference tournament games decided by kicks from the mark, which the NCAA treats as ties for statistics purposes. According to the NCAA description of the rule change, since 2013 47% of tied games going to overtime ended up still tied at the end of overtime. Putting the numbers together, this suggests that roughly 23% of games were tied at the end of regular time. Thus a good guess is that under the new rule 23% of games will be ties.
It is possible that teams will make tactical adjustments that will affect the percentage of tied games. It seems unlikely to me that this would have a big effect on the expected 23% of games tied.
How Will This Affect Individual Team Ratings and Ranks?
The change can affect all three elements of a team’s RPI. Obviously, the change will affect the team winning percentage (Element 1), if the team would have won or lost a game in overtime but instead ends up with a tie. But in addition, the change will affect the team’s opponents’ winning percentages (Element 2) if those opponents would have won or lost games in overtime but instead end up with ties. And it likewise will affect the team’s opponents’ opponents’ winning percentages (Element 3). Thus the change will affect both teams’ winning percentages and their strengths of schedule (Elements 2 and 3).
For illustration, I ran a test for the 2019 season, using the NCAA’s data to change games won or lost during overtime to ties. Here is the first of several tables based on that test. It covers the top 10 automatic qualifiers (conference champions) based on RPI ratings and ranks as they would have been under the new rule. It compares those ratings and ranks to the actual ratings and ranks under the old rule. The ranks are in the highlighted columns on the right.
As you can see if you look at the top 3 of Stanford, North Carolina, and South Carolina, they have no changes in their own win-loss-tie records yet their RPI ratings changed. The rating changes are due to their opponents and/or their opponents’ opponents having changes in their win-loss-tie records. The rating changes do not affect the Stanford and North Carolina ranks. South Carolina, however, drops from #5 to #6. This is due to the change in its rating (resulting from changes in its strength of schedule) combined with changes in the rating of the team that moves up to #5 (which happens to be Arkansas) and also is affected by how close those two teams are in the ratings. This illustrates that there are a lot of moving parts that contribute in varying degrees, depending on the data, to the effect of the rule change on a particular team.
Looking at 2019 from high above, the maximum rank change for any team is 52 positions. This is for Oral Roberts, which has two games it won in overtime converted to ties. Oral Roberts is in the middle of the Division I rankings where team’ ratings tend to be much close together than at the top and bottom of the rankings, so that a relatively small rating change can result in a relatively large rank change. The smallest rank change is 0 positions, as the numbers for Stanford and North Carolina show. The average rank change is 10.7 positions and the median is 8.
How Will This Affect Conference Ratings and Ranks?
Continuing with the 2019 season as an example, the following table shows conference teams’ average RPI ratings and ranks and how the conferences rank in relation to each other under the two systems. Although the average ranks of teams in conferences change, there are not major changes in how the conferences rank in relation to each other.
How Will This Affect the NCAA Tournament Bracket?
To show how the change will affect the NCAA Tournament bracket, I will go through a series of similar tables, again for the 2019 season. After the first table, I will explain what it shows.
This table shows all of the 2019 automatic qualifiers. That is what the lime green highlighting signifies. You can look at each one to see how its record changes under the new rule and also how its RPI rank changes.
I will not explain the entire table yet, but an important column is the NCAA Tournament Seed or Selection column. That column uses a number code for the NCAA Tournament decision the Committee made for that team:
1 #1 seed
2 #2 seed
3 #3 seed
4 #4 seed
5 Unseeded automatic qualifier
6 Top 60 team in the actual 2019 RPI ranks that got an at large selection
7 Top 60 team in the actual 2019 RPI ranks that did not get an at large selection
To consider likely effects of the new rule, it helps to know that historically #1 seeds always have come from teams ranked #7 or better, #2s from teams ranked #14 or better, #3s from teams ranked #23 or better, and #4s from teams ranked #26 or better. Further, teams ranked #30 or better (that are not automatic qualifiers) always have gotten at large selections. And teams that are ranked #58 or poorer never have gotten at large selections. What you want to be looking for are teams that have moved in and out of these ranges as a result of the rule change.
Here is the next table:
This is all of the teams, not automatic qualifiers, that are in the Top 30 under the new rule. That is what the dark green highlighting signifies. You will see that in the NCAA Tournament Seed or Selection column, I have highlighted two cells in dark green. Each cell contains the number 7, which means that the team was in the RPI Top 60 but the Committee did not give it an at large selection. The cells are for Florida Atlantic and Yale. If you compare the actual RPI ranks to the OT Only in Tournament Games ranks for these teams, you will see that Florida Atlantic, due to the rule change, moves from #32 to #20 in RPI rank and Yale moves from #37 to #25. Thus both teams moved from outside the #30 or better historically "protected" area to inside the protected area. Because of this, it is reasonable to believe that both Florida Atlantic and Yale would have gotten at large selections, which means that two teams that actually did get at large selections would not have gotten them. (The two teams that move out of the Top 30 are Florida and Louisville, which means they move from protected to the bubble.)
You also will see, in the NCAA Tournament Seed or Selection column, that I have grey highlighting for a number of cells. These are for teams where the change in its RPI rank due to the new rule suggests that the team might have -- or definitely would have, according to the seed ranges -- gotten a different seed result from the Committee.
If you look at Santa Clara in the table, you will see something interesting. It had no overtime games decided by a golden goal, so its record is unchanged. Its rank, however, moves up from #29 to #17, a pretty significant improvement. Since its own record is unchanged, this means all of the rank change is due to a change in the Santa Clara strength of schedule and/or to other teams moving to poorer ratings as a result of the rule change. On looking at the changes for the teams Santa Clara played in 2019, they have 13 golden goal wins converted to ties and 22 golden goal losses converted to ties, the net effect of which would be an improvement in Santa Clara’s strength of schedule. Santa Clara thus gives a good illustration of how a team can have no change in its own record but nevertheless move significantly in the rankings due to all of the other moving parts in the rating system.
Here is the last table. It includes data for all of the teams (not automatic qualifiers) ranked between #31 (of the new rule ranks) and #57 of either of the actual 2019 ranks or the new ranks.
A key column in this table is the RPI Rank and Top 50 Results Rank Rank column. This column shows the ranks of teams based on combining their RPI ranks and their Top 50 Results Ranks, each weighted at 50%. Top 50 Results Ranks are based on my own scoring system for good results (wins or ties) against Top 50 opponents -- it essentially is a measure of how high in the rankings a team has shown it is able to be successfully compete. This is a key column because historically, if I use this column to predict Committee at large selections from among the teams ranked #31 through #57, on average it matches all but two of the Committee selections each year.
Wake Forest moves up from actual #61 (outside the bubble) to #54 (inside the bubble). The red highlighting in the NCAA Tournament Disqualified column, however, indicates it actually had a winning percentage below 0.500 (which it likewise has under the new rule), so it is not eligible for an at large position.
Mississippi and Georgia both were within the actual top 57 and thus could have been considered bubble teams. Under the new rule, however, they both fall out of the bubble group. As the NCAA seed or selection column indicates, neither got an at large selection, so the rule change does not affect their NCAA Tournament status.
Denver and Boston College move up from actual #66 and #77 to #57 and #56 respectively so that both now can be considered in the bubble. According to the RPI Rank and Top 50 Results Rank Ranks, however, they do not get at large positions, so the rule change does not affect their likely NCAA Tournament status.
Looking at 2019 as a whole, under the new rule it appears there would have been some NCAA Tournament seed changes (although nothing suggests changes in the four #1 seeds). As I look at the at large selections, it appears that the last of the bubble teams likely would have been Notre Dame, Georgetown, Iowa, TCU, Washington State, and Utah, which are, in order, the bottom teams in the RPI Rank and Top 50 Results Rank Ranks. All of those teams got at large selections in 2019, but most likely three of them do not get at large selections under the new rule.
Additional Comments
Looking at the above information for the 2019 season, the changes for particular teams and conferences appear relatively random. If the test were to include more seasons, perhaps patterns would appear, but I do not see them at this point.
The test does seem, however, to give a picture of how big the effect of the rule change is likely to be on the NCAA Tournament bracket. In essence, it likely will mean a few differences in seeds and a few different teams getting at large selections than would have been the case under the old rule, with the differences being relatively random.
This assumes that the Committee will not make significant adjustments in how it makes its bracket decisions, in response to the new rule. Practically speaking, I think this is a pretty good assumption. The Committee, as will be the case for all of us, will be looking at data very similar to the data it has had in the past except that there will be more ties. It is hard to imagine anything changing in the Committee thought process simply because there are more ties.
There is one possible way I can think of in which the change might affect a particular class of teams. It is possible that teams with better bench depth have an advantage in overtime games. If this is the case, then eliminating regular season overtime games may work against these teams. I suspect, however, that any change would be subtle, as teams with better bench depth may be able to make tactical adjustments to offset the loss of any advantage in overtime games.
