防御率计算器 — 公式
## How ERA Is Calculated
### Formula
**ERA = (Earned Runs / Innings Pitched) x 9**
ERA normalizes to a 9-inning game so you can compare pitchers with different workloads.
### Benchmarks
- **Below 3.00**: Excellent (ace-level)
- **3.00-3.50**: Very good
- **3.50-4.00**: Above average
- **4.00-4.50**: Average
- **Above 5.00**: Below average
### Formula
**ERA = (Earned Runs / Innings Pitched) x 9**
ERA normalizes to a 9-inning game so you can compare pitchers with different workloads.
### Benchmarks
- **Below 3.00**: Excellent (ace-level)
- **3.00-3.50**: Very good
- **3.50-4.00**: Above average
- **4.00-4.50**: Average
- **Above 5.00**: Below average
计算示例
A pitcher allowed 30 earned runs in 100 innings.
- ERA = (30 / 100) * 9 = 0.30 * 9 = 2.70
- This is an excellent ERA