This K/9 calculator is a vital tool in baseball analytics for measuring a pitcher’s strikeout efficiency using K/9 = (K / IP) × 9 formula.
K/9, short for “strikeouts per nine innings,” quantifies how many batters a pitcher would theoretically strike out if they pitched a complete game.
For instance, imagine a pitcher who strikes out 6 batters in 6 innings. Their K/9 would be:
(6 strikeouts / 6 innings) * 9 = 9 K/9This indicates the pitcher averages 9 strikeouts per nine-inning game, a solid performance in most leagues.
K per 9 Calculator
| Strikeouts | Innings Pitched | K/9 | Interpretation |
|---|---|---|---|
| 200 | 180 | 10.00 | Elite |
| 150 | 160 | 8.44 | Very Good |
| 120 | 150 | 7.20 | Average |
| 80 | 140 | 5.14 | Below Average |
| 220 | 200 | 9.90 | Very Good |
| 175 | 200 | 7.88 | Average |
| 90 | 110 | 7.36 | Average |
| 130 | 120 | 9.75 | Very Good |
| 50 | 90 | 5.00 | Below Average |
| 300 | 250 | 10.80 | Elite |
| 160 | 175 | 9.17 | Very Good |
| 140 | 160 | 7.88 | Average |
| 60 | 100 | 5.40 | Below Average |
Strikeouts Per 9 Innings Formula
The formula for calculating K/9 is straightforward:
K/9 = (Total Strikeouts / Innings Pitched) * 9Where:
- K = Total number of strikeouts.
- IP = Total number of innings pitched.
- K/9 = Strikeouts per 9 innings.
Consider a pitcher who has accumulated 120 strikeouts over 150 innings:
K/9 = (120 / 150) * 9 = 0.8 * 9 = 7.2This pitcher averages 7.2 strikeouts per nine innings, showcasing above-average strikeout ability.
How To Calculate K per 9?
Calculating K/9 involves a simple process:
- Gather data: Collect the pitcher’s total strikeouts and innings pitched.
- Divide strikeouts by innings: This gives you strikeouts per inning.
- Multiply by 9: Scale to a full game equivalent.
A pitcher has 85 strikeouts in 95 innings.
K/9 = (85 / 95) * 9 = 0.8947 * 9 ≈ 8.05This pitcher boasts an impressive 8.05 K/9, indicating they’re quite adept at retiring batters via strikeout.
What is a Good K per 9?
In modern Major League Baseball:
- Elite: 10+ K/9
- Very Good: 8-10 K/9
- Average: 7-8 K/9
- Below Average: <7 K/9
For example, in 2023, Gerrit Cole led the American League with an outstanding 11.53 K/9, exemplifying elite strikeout prowess.
A high school pitcher with a 7 K/9 might be considered exceptional, while the same rate in the MLB would be average.
Sources
- FanGraphs – K/9 (Strikeouts per Nine Innings)
- MLB.com – Statcast Leaderboard
- Baseball Reference – Standard Pitching Statistics
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