Recalculating Player Value: Jansen, Turner, & Weaver
With the season underway, owners need to start adjusting some player’s fantasy value. Some of the tweaks can be from talent changes (e.g. increase in talent) or role (e.g. moving for a long reliever to starter). Three players, Kenley Jansen, Trea Turner, and Luke Weaver, are three such players on the move.
The concern with the 30-year-old righty is his fastball (cutter) velocity dropping from 93.3 mph to 91.2 mph.
The news has improved over the past couple days as the velocity has trended up. He may or may not be able to keep the gains and we don’t know where his talent will level out. Even without this information, his talent can be estimated at a lower fastball velocity for future reference.
The key behind estimating his talent is finding his cutter results at different velocities. By grouping his cutter results into 1 mph increments, here are its swinging strike rates over the past three seasons.
The slope is steady with a r-squared of .98 and the SwStr% equation of:
SwStr% = .0204*FCv -1.74
The next key is to give the pitch an ERA based on its SwStr%. This procedure can be done using my pERA metric with gives each pitch an ERA value and combines them for an overall ERA estimator.
Assuming a steady 32% GB% on the cutter, here’s it’s projected ERA at different velocities
| Velocity | SwStr% | pERA |
|---|---|---|
| 88 | 5.5% | 4.83 |
| 89 | 7.6% | 4.33 |
| 90 | 9.6% | 3.83 |
| 91 | 11.6% | 3.33 |
| 92 | 13.7% | 2.83 |
| 93 | 15.7% | 2.33 |
| 94 | 17.8% | 1.84 |
| 95 | 19.8% | 1.34 |
| 96 | 21.8% | 0.84 |
With the new cutter pERA, I just have to make a few talent assumptions to estimate Jansen’s overall value. The assumptions are:
- His slider will remain as effective (0.00 pERA)
- His pitch mix will stay the same (90% cutter, 10% slider). He’s closer to 85%/15% this season.
- Maintains the same amount of control (BB% constant, -0.3 to his ERA)
And here are the results:
| Velocity | Overall ERA |
|---|---|
| 88 | 4.05 |
| 89 | 3.60 |
| 90 | 3.15 |
| 91 | 2.70 |
| 92 | 2.25 |
| 93 | 1.80 |
| 94 | 1.35 |
| 95 | 0.90 |
| 96 | 0.45 |
The results are not catastrophic if he loses 2 mph but he moves from elite status into more of a middle-of-the-pack closer. Greg Holland had a similar decline from his Royals peak with back-to-back sub-2.00 ERA seasons with a 96-mph fastball to the past couple seasons with a 93.5 mph fastball and a 3.50 ERA.
Jansen may keep up his last appearance’s velocity and be his old self. If not, fantasy managers need not freak out as he’s likely to still be a decent closer.
Last week I wrote about Trea Turner moving down in the Nationals lineup. Now, I’m finding out how much fantasy value it cost him.
This calculation is easier after I created a simple tool earlier this offseason to estimate counting stat changes. Making the assumption Turner will playing 90% of the Nationals games and the team scores 5.0 Runs per game, his here are the projected Runs and RBI’s from the 1st and 6th lineup spots.
| Lineup Position | PA | Runs | RBI |
|---|---|---|---|
| First | 696 | 96 | 63 |
| Sixth | 615 | 66 | 92 |
| Change | -81 | -30 | 29 |
The Run+RBI total stays constant has the Run total switch over to RBI’s. An owner may be forced to deal with this change later in the season with a trade to balance their team.
The biggest difference is in the plate appearances. According to our projections, Turner was expected to steal a base once every 12.6 PA. He’ll lose the opportunity for about 6.5 steals over the course of a season. Eyeballing the difference in six steals with our auction calculator, his value drops about $1.5 in a 15-team league. Decent but not huge.
There isn’t much Turner’s owners can do about the move though. If they drafted him for steals, they aren’t going to find a 40+ stolen base guy on the waiver wire. They are just going to have to ride out the move.
Owners in point based leagues like Ottoneu will be hurt the most as the 80 fewer plate appearances will affect his total points. Those owners may be able to move him at his preseason full value.
After digging around this preseason and into the season to find pitchers with effective new pitches, I was only able to find German Marquez. I now have a second one, Luke Weaver, and his hard curve. While he did throw a curve last season, this one is 2 mph faster and he’s using it 20% of the time.
Here’s a look at the pitch.
This pitch makes him better for a couple reasons. First, it gives him a third pitch to help him navigate a lineup multiple times as hitter can’t just sit on his fastball and change.
Second, it’s a breaker he can throw for strikes if behind in the count. His changeup is a great swing-and-miss pitch but it’s rarely in the strike zone (37%). In a small sample this season, the curve is in the zone 63% of the time.
He’s better with the pitch than without it but how much better is tough to figure out. Luke Weaver’s NFBC ADP ended at 108th overall. Other starters around his value were Jake Arrieta, Jose Berrios, and Kyle Hendricks. I’d probably value him similarly to the pitchers in the 65-75 ADP range (Jose Quintana, Dallas Keuchel, and James Paxton) for now. Owners can look to possibly buy at pre-season prices and get a small value bump.
Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR twice, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.
The spreadsheet you linked to in the Trea Turner post is great. I am surprised to find that the 5th spot in the lineup on average produces the most RBI. I’d have guessed 4th.
Thank you. Interesting evaluation. Considering the injury history for Eaton, it may be hard to pin just where Turner will bat for the majority of the season. Even though his steal attempts could decrease with batting in the middle-third of the lineup, some of the reasoning from Dave Martinez was that Turner would be able to run more effectively when he doesn’t have to worry about his steals impacting at-bats for their biggest run producers. Not sure how that could be quantified but is it possible he could steal more frequently batting mid-third even if total number of steals deceases?
FWIW the Dodgers traced Jansen’s velo dip to a mechanical problem from his ST hamstring tweak, and as soon as they recognized it (complete with a changed release point and the reduced velocity), he looked normal again in velo, movement and release point.
Also, Jansen’s got a happy place at 93mph with his cutter. Jansen doesn’t use a cutter grip, he throws with a 4 seam grip and his gigantic hands put the cut on the ball naturally. When Jansen dials his velocity up to 95-96 (which he can do), the pitch straightens and is recognized by Trackman as a 4 seam fastball. He sometimes does this on purpose when he’s trying to go for the elevated fastball for the strikeout.
That’s why projecting results purely based on velocity isn’t that effective; Jansen would be a less effective closer throwing a consistent 95-96 than he is at 92-93 due to the loss of cutting action on the pitch.
If he could throw with the cut at 96, it might be different, but he can’t do that.
so, how do you square this theory with him being 90% cutter 10% slider according to the article?
Let me put it another way for you, tracman may get that pitch wrong, but fangraphs doesn’t. The chart shows the swinging strike rate for the 95 MPH pitch, regardless of what tracman calls it during a game. It’s a good pitch at 93, it’s amazing at 95.
Your message would be better received without a condescending tone. I have seen a ton on Kenley – he is almost always lights out – velo is not generally an important part of the equation. One thing that is not in those charts is the sample sizes. Those upper 80s pitches are probably all from bad nights – most in the past couple weeks and there probably isn’t many of them. I wouldn’t be surprised if those 95+ pitches aren’t mainly chase pitches in 0-2 counts or something like that. The elite Kenley that I know and love works in the low 90s more often than not. I would wager that those upper 90s FBs are elevated – they are going to generate swings and misses. Kenley doesn’t succeed entirely on Ks, he gets lots of weak swings. The K story is compelling, but there is a lot more to it than that.
Jansen introduced his slider in 2017 and featured it more than he had previously, almost exclusively as a 2 strike out pitch (often after a foul ball or two), where it was devastating.
His command of it is quite good and he’s been using it more and more frequently. He has been in more trouble spots this year and so it makes sense for the slider usage to be up; in 2017 he did not use it unless he needed it (which is what made it so potent; hitters can never prepare for it).
This is also why his pitches at 95+ are so effective: because the hitter has to be so focused on the Jansen cutter, when he actually changes pace it is supremely effective because it’s basically always a surprise.
As a hitter you can’t go up expecting to see either cutter or slider, because it’s almost always cutter..til the 7th or 8th cutter in a row turns into the slider from the same arm slot and arm speed.
He effectively uses it the way a lot of pitchers use a rarely-thrown changeup for ugly swing and miss; it wouldn’t work if it was expected.
The cutter’s good enough that he can throw it predominantly and use the other stuff only when he needs an extra edge.
When he just threw 95 all the time in the minors he wasn’t nearly as good because it’s not an elite 4 seamer; when the ball suddenly rises instead of cutting, though, good luck.
Weird how you had down votes as of this reply. People just don’t like what you have to say? It sounds like you are actually familiar with Jansen’s arsenal.. as am I. He is so smart about how he throws breaking balls – he never misses in a bad spot and almost always buries it. Have you noticed how frequently he is working up in the zone? I think that may be his real problem. Cutters up are not a great idea.
So has Didi’s value increased enough to warrant a trade for Turner. All of Didi’s metrics have completely flipped in the first two weeks of the season. His plate discipline has exploded as he’s walking at a 18.5% clip. He’s not chasing and hitting everything in the zone. His BABIP is .256 and he’s batting. 327! Is Didi for real or should I trade him for Turner in hopes that Turner’s slow start will turnaround?
You should do that trade, can’t imagine the other owner will though!
He did it! And I now have an uncomfortable feeling of regret. Don’t get me wrong I love Turner, but Didi looks like an MVP type player thus far. I think I’ll feel better when Turner swipes 70 bags.
That is a really nice piece of data for Jansen. Ouch! I pretty much never say that – well done.