Instant Replay Review Statistics 101: Week 1 Sabermetrics

MLB's new Instant Replay Review process is sabermetrics personified: With 47 reviews through 101 games played, we can expect to see over 1,000 more Replay Reviews by Game 162 (or 2430, cumulatively). Such a relatively large data set will, in time, lend itself to extensive strategic analysis not seen with ejections, which often take five full seasons to accumulate to such a sample size. As the numbers and trends begin to form (albeit in a highly preliminary stage), Close Call Sports and the Umpire Ejection Fantasy League provides the following Replay Review Sabermetrics primer. First, some key terms:

Review Affirmation Percentage (RAP): The percent of Replay Reviews in which an umpire's call is confirmed or upheld (stands). For instance, a RAP of .750 for n=4 indicates that three calls were affirmed (confirmed/stands) via Replay Review while the other was reversed (overturned). A higher figure (trending towards 1.000) indicates greater calling accuracy; a lower figure (trending towards .000) indicates a greater real-time call error rate. Also known as QOC (Quality of Correctness).

Replay Percentage of Success (RPS): The percent of Replay Reviews in which a ball club and/or its Manager receives an overturned call that benefits the team. Includes both Crew Chief Reviews (initiated by the umpires) and Manager's Challenges (initiated by the teams). For instance, RPS of .333 for n=3 indicates that two calls were affirmed (confirmed/stands) via Replay Review while the other was reversed (overturned). Alternatively, 1.000 - RAP = RPS.

Manager's Challenge Success Percentage (CSP): A subset of RPS, this statistic considers just those Replay Reviews that were effected as the result of a Manager's Challenge. For both RPS and CSP, a higher number (1.000) indicates greater success in the Replay Review process; a lower figure (.000) indicates less successful outcomes.

With Week 1 of the MLB Regular Season in the books, the UEFL recaps professional baseball's "this time it counts" living experiment with Instant Replay Reviews. Bearing in mind that with n=47, our sample size is relatively small and unreliable, here are the "early returns" numbers:

Key bullet points:
"Teams Most Used" (Made use of Replay Review most often): Yankees & Athletics - 4
"Manager's Challenge Leaders" (Most challenges filed): Rick Renteria, Brad Ausmus, Joe Maddon - 3.
"Most successful Manager" (Manager with highest CSP): Fredi Gonzalez - 1.000 in 2/2.
"Least successful Manager" (Manager with lowest CSP): Melvin, Gibbons & Williams - .000 in 0/2.
"Umpire most questioned" (Ump with most Replay Reviews): Bob Davidson & Dana DeMuth - 3.
"Most accurate umpire" (Umpire with greatest RAP): Jerry Layne & Jim Wolf - 1.000 in 2/2.
"Umpire of greatest overturn %" (Umpire with lowest RAP): Chris Conroy - .000 in 0/2.
"Overall affirmation or QOC percentage" (Overall RAP): .660 (31/47 Affirmed Replay Reviews).
Team Status Pre-Review (Winning or Losing prior to review [Win-Loss-Tied]): 17-18-12.
Team Status Post-Review (Won or Lost the game [Wins-Losses]): 21-26. (Delta: 4-8; WPCT: .333).*
*This .333 winning percentage resembles the mid-.330s Win % associated with post-ejections.

Actual data:
Games Played: 101
Replay Reviews and Decisions Rendered: 47 (on pace for 1,130 reg. season Replay Reviews)
- Crew Chief Reviews (Replay Reviews initiated by the Umpiring Crew Chief): 9 (19%)
- Manager's Challenges (Replay Reviews initiated by the Club's Field Manager): 38 (81%)

Teams Most Used - Quantity of Replay Reviews (both Crew Chief & Manager's Challenge)
1. New York Yankees: 4 (2 Crew Chief Reviews [1.000 RAP], 2 Challenges [.500 RAP]).
1. Oakland Athletics: 4 (2 Crew Chief Reviews [1.000 RAP], 2 Challenges [1.000 RAP]).
3. Chicago Cubs: 3 (3 Challenges [.667 RAP]).
3. Colorado Rockies: 3 (1 Crew Chief Review [1.000 RAP], 2 Challenges [.500 RAP]).
3. Detroit Tigers: 3 (3 Challenges [.333 RAP]).
3. Tampa Bay Rays: 3 (3 Challenges [.333 RAP]).
3. Toronto Blue Jays: 3 (1 Crew Chief Review [1.000 RAP], 2 Challenges [1.000 RAP]).

Most Successful Managers - Managers with Highest CSP
1. Fredi Gonzalez (Atlanta Braves): 1.000 CSP (2/2 Challenges Overturned).
2. Ron Gardenhire (Minnesota Twins): 1.000 CSP (1/1 Challenge Overturned).
2. Terry Collins (New York Mets): 1.000 CSP (1/1 Challenge Overturned).
4. Brad Ausmus (Detroit Tigers): .667 CSP (2/3 Challenges Overturned).
4. Joe Maddon (Tampa Bay Rays): .667 CSP (2/3 Challenges Overturned).

Least Successful Managers - Managers with Lowest CSP
1. Bob Melvin (Oakland Athletics): .000 CSP (0/2 Challenges Overturned).
1. John Gibbons (Toronto Blue Jays): .000 CSP (0/2 Challenges Overturned).
1. Matt Williams (Washington Nationals): .000 CSP (0/2 Challenges Overturned).
4. John Farrell (Boston Red Sox): .000 CSP (0/1 Challenge Overturned).
4. Robin Ventura (Chicago White Sox): .000 CSP (0/1 Challenge Overturned).
4. Don Mattingly (Los Angeles Dodgers): .000 CSP (0/1 Challenge Overturned).
4. Mike Redmond (Miami Marlins): .000 CSP (0/1 Challenge Overturned).
4. Ryne Sandberg (Philadelphia Phillies): .000 CSP (0/1 Challenge Overturned).

Most Accurate Umpires - Umpire with greatest RAP
1. Jerry Layne: 1.000 RAP (2/2 Challenges Affirmed).
1. Jim Wolf: 1.000 RAP (2/2 Challenges Affirmed).
3. Jordan Baker, Sean Barber, Lance Barrett, Ted Barrett, CB Bucknor, Vic Carapazza, Kerwin Danley, Clint Fagan, Manny Gonzalez, Chris Guccione, John Hirschbeck, Brian Knight, Jerry Meals, Jim Reynolds, Mark Ripperger, Tim Timmons, Mark Wegner, Joe West, Mike Winters, Quinn Wolcott: 1.000 RAP (1/1 Challenge Affirmed).

Umpire of Greatest Overturn % - Umpire with lowest RAP
1. Chris Conroy: .000 RAP (0/2 Challenges Affirmed).
2. Cory Blaser, Mike DiMuro, Marty Foster, Greg Gibson, James Hoye, Gabe Morales, Mike Muchlinski, Dale Scott, John Tumpane: .000 RAP (0/1 Challenges Affirmed).