In baseball statistics, defense-independent ERA (dERA) is a statistic that projects what a pitcher's earned run average (ERA) would have been, if not for the effects of defense and luck on the actual games in which he pitched. The statistic was first devised by Voros McCracken in 1999.

Method

Version 2.0 of dERA uses the following statistics: 0) Multiply BFP by .0074 to get the number of intentional walks allowed (dIBB).

1. Divide HB by BFP-IBB. Call this $HB. Then multiply $HB by BFP-dIBB. This number gives the DIPS number of Hit Batsmen (dHB).
2. Divide (BB-IBB) by (BFP-IBB-HB), and call this number $BB. Multiply BFP by 0.0074, and call this dIBB.
3. Divide K by (BFP-HB-BB) and call this number $K. Remember this number for later.
4. Divide HR by (BFP-HB-BB-K) and call this number $HR. Remember this number for later.
5. Calculate the number of 'Balls Hit in the Field of Play'. This is BFP-dHR-dBB-dK-dHB.
6. Estimate hits per balls in the field of play ($H):
7. To get the projected number of Hits Allowed (DIPS 'Hits Allowed', or dH), multiply $H by the number of balls hit in the field of play (BHFP).
8. Take BFP-dBB-dHB-dK-dH and multiply that number by 1.048. Add dK to that number. Take that number and divide by 3. This is the DIPS total of Innings Pitched (dIP).
9. Sum the following products: The sum of all of these is the DIPS total of earned runs (dER).
10. Calculate ERA as usual: (9*dER)/dIP. This is the DIPS ERA (dERA).

Alternative formulation