I’m in the process of rolling out more stats based on Match Charting Project data across Tennis Abstract. This is one of several glossaries intended to explain those stats and point interested visitors to further reading.
- RiP% – Return in play percentage. The percent of return points in which this player got the serve back in play.
- RiP W% – Return in play winning percentage. Of points in which the returner got the serve back in play, the percentage that the returner won.
- RetWnr% – Return winner percentage. The percentage of return points in which the return was a winner (or induced a forced error).
- Wnr FH% – Return winner forehand percentage. Of return winners, the percentage that were forehands (topspin, chip/slice, or dropshot).
- RDI – Return Depth Index, a stat recently introduced at Hidden Game of Tennis. The Match Charting Project records the depth of each return, coding each as a “7” (landing in the service box), an “8” (in back half of the court, but closer to the service line than the baseline), or a “9” (in the backmost quarter of the court). In the original formulation, RDI weights those depths 1, 2, and 4, respectively, and then calculates the average. I’ve tweaked it a bit to reflect the effectiveness of various return depths. For men, the weights are 1, 2, and 3.5, and for women, the weights are 1, 2, and 3.7.
- Slice% – Slice/chip percentage. Of returns put in play, the percent that are slices or chips, including dropshots.
The return stats leaderboards also show most of these stats for first-serve returns only, and for second-serve returns only.