In memory of
Although it's a few weeks before too much will be made of these, I have begun calculating various measures of team success in 2014. This is an introduction to some of the analysis included on this site.
These ratings are published daily along with some meta-rating variations:
| nRPI |
The RPI is the "standard" NCAA measure of team results. "Standard" has to be in quotes because the committee responsible for
each sport's tournament is allowed to make whatever changes it wants to the basic formula.
nRPI is the variation adopted by the baseball committee beginning in 2013. It replaced a system of bonuses and penalties for top-team wins and bottom-team losses or playing too many games vs non-D1 opponents with a definition of winning percentage1 that gives less value to home wins and road losses and more to road wins and home losses. The base RPI formula is simpler to state than it is to explain. It is 25% winning percentage plus 50% oppenents' winning percentage (OWP2) plus 25% Opponents' Opponents winning percentage (OOWP3). I publish the nRPI with a comparison to the base and the SOS components of the formula (which are the same for both variants) but for any analysis that depends upon opponents' values I only use the base RPI values. |
| RPI | |
| ISRm |
Boyd Nation's ISR as amended for home field advantage (Tweaking the ISR's)
and margin of victory.
I label this ISRm to distinguish it from the ISR without the margin of victory adjustment, to which I may occasionally refer. Unless explicitly stated otherwise textual references to ISR are based upon the ISRm calculation. |
| ISOV |
The Iterated Strength of Victory is my modification of the ISR algorithm that uses a variable adjustment for each game based
upon the SOV4 for each game compared to the mean SOV for all games.
The ISOV is to the (original) ISR as Jeff Sagarin's "pure points" is to his "ELO Chess" rating. It is not as good a measure of past performance as the ISR or RPI but it is useful in that it provides a mechanism for a SOS-adjusted scoring stats, which in turn can be used to provide a predictive rating. |
| PA(rating) | This is the basic report to analyze game results according to the specific rating.
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| vs Opp Ranks | Records vs Opponents' rating Ranks is an index to the "gory details" for each team sorted by a "better wins compared to worse losses"5 algorithm.
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| Interconference Analysis |
Interconference results weighted by opponents' rating values.
The detail section includes a line for each opposing conference that serves as an index to the interconference results in descending WP order.
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| Normalized Scoring |
This uses the SOS as defined by opponents' ISOV ratings to adjust runs-scored and -allowed.
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| Second-order WP |
This report is described in Too early Ratings. The column headings are:
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| 1 | RPIwins = 0.7×HomeWins+1.3×RoadWins+NeutralWins RPITies = 0.7×HomeTies+1.3×RoadTies+NeutralTies RPILosses = 0.7×RoadLosses+1.3×HomeLosses+NeutralLosses
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| 2 | OWP is the average of opponents' winning percentage not including games against the team for which OWP is calculated. | ||||
| 3 | OOWP is the average of opponnets' OWP values. Note that this does include results of games involving the team for which OOWP is calculated. | ||||
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| 5 | The "better wins compared to worse losses" algorithm
uses the opponent rank to assign a value to the win (or loss). sort value = (#teans+1 - opponent rank) for wins minus opponent rank for losses over all games played. Higher values are better. |
In memory of