ERA Equivalent WHIP (or Why Yusei Kikuchi is Unrosterable)

Every week, I look through my rostered pitchers noting the worst ones and churn them out next week. This week, the Yusei Kikuchi stood out. Someone with a 3.06 ERA and his ERA estimators around 4.50. It was his ERA estimators throwing red flags, but I have other pitchers worse. It was his 1.52 WHIP, third worst among qualified starters behind Kyle Freeland (1.63) and Jack Kochanowicz (1.56). With WHIP being its own Roto category, it has as much weight as ERA but ERA is the mentioned multiple times more often than WHIP. I’m just going to create a simple WHIP to ERA conversion to put both on the same scale.
To get the conversion equation, I used the overall rankings for the NFBC’s Main Event (15 team) and Online Championship (12 team). With them, I ranked the WHIP and ERA values separately. I removed the the first and last 10% of values because the change for them isn’t linear.
With the tails removed and plotted the best remaining WHIP with the best remaining ERA. I did that for each one. Here are the plotted results.
The correlation is nearly perfect, so the correlation equations can be used to convert a WHIP to an ERA equivalent. Here is conversion table.
WHIP | ME Eqiv ERA | OC Eqiv ERA |
---|---|---|
0.70 | 0.48 | 0.52 |
0.80 | 1.09 | 1.12 |
0.90 | 1.70 | 1.72 |
1.00 | 2.31 | 2.33 |
1.10 | 2.92 | 2.93 |
1.20 | 3.53 | 3.53 |
1.30 | 4.14 | 4.13 |
1.40 | 4.75 | 4.73 |
1.50 | 5.36 | 5.33 |
1.60 | 5.97 | 5.94 |
1.70 | 6.58 | 6.54 |
1.80 | 7.19 | 7.14 |
1.90 | 7.80 | 7.74 |
2.00 | 8.41 | 8.34 |
The results for the two league types are close so I’ll only use the Main Event information going forward. Besides the above table, I have created a public Google Sheet (copy by going to File -> Make a Copy) where a WHIP can be entered and an equivalent ERA is spit out.
Kikuchi’s 1.52 WHIP would be equivalent to a ~5.50 ERA. No one is starting/rostering a pitcher with a 5.50 ERA this deep into the season. The high WHIP can’t be ignored and I’m likely to move on where I can find decent options.
Besides Kikuchi, Here are the qualified pitchers who have a WHIP that does as much ratio damage as a 4.50 or worse ERA.
Name | ERA | WHIP | equivalent ERA | NFBC Main Event Roster% |
---|---|---|---|---|
Kyle Freeland | 5.72 | 1.63 | 6.15 | 4% |
Jack Kochanowicz | 5.34 | 1.56 | 5.72 | 4% |
Yusei Kikuchi | 3.06 | 1.52 | 5.48 | 98% |
José Soriano | 3.41 | 1.51 | 5.42 | 98% |
Randy Vásquez | 3.99 | 1.47 | 5.18 | 42% |
Gavin Williams | 3.79 | 1.45 | 5.05 | 100% |
Luis L. Ortiz | 4.40 | 1.43 | 4.93 | 91% |
Max Meyer | 4.73 | 1.42 | 4.87 | 100% |
Sean Burke | 4.20 | 1.42 | 4.87 | 28% |
Jonathan Cannon | 4.66 | 1.40 | 4.75 | 21% |
Michael Lorenzen | 4.33 | 1.40 | 4.75 | 98% |
Zac Gallen | 5.54 | 1.40 | 4.75 | 100% |
Dean Kremer | 4.70 | 1.39 | 4.69 | 81% |
Jeffrey Springs | 4.72 | 1.38 | 4.63 | 97% |
Shane Baz | 4.92 | 1.38 | 4.63 | 100% |
Andre Pallante | 4.23 | 1.36 | 4.50 | 86% |
Chris Bassitt | 3.80 | 1.36 | 4.50 | 97% |
Gavin Williams and José Soriano have been devastating managers’ in the WHIP category but it doesn’t seem as bad with sub-4.00 ERA.
WHIP is probably one of the most misunderstood categories and hopefully I made it easier to understand an expectable value.