| Abbreviation | Definition |
|---|---|
| RA | Runs Allowed |
| RBA | Rangers Baseball Arlington |
| RBA | Richmond Baseball Academy |
| RBF | Riverside Baseball Federation |
| RBI | Reaching Baseball Ideals |
| RBI | Recycled Baseball Items |
| RBI | Reviving Baseball in |
| RBI | Reviving Baseball in Inner |
| RBI | Run(s) Batted In |
| RBL | Riecker Baseball League |
| RBSA | Ramsey Baseball and Softball Association |
| RBY | Redlands Baseball for Youth |
| RCAA | Runs Created Above Average |
| RD | Run Differential |
| RLB | Replacement Level Baseball |
| RLB | Rock League Baseball |
| RMBL | Rocky Mountain Baseball League |
| ROE | Reached base On Error (in baseball) |
| ROE | Reached On Error |
| RRBL | Round Rock Baseball League |