John Jaso Compared to NL Central First Baseman: Matt Adams

John Jaso has played well as the Pittsburgh Pirates starting first baseman, but how has he compared to the other National League first baseman? A look at St. Louis Cardinals first baseman Matt Adams.

The Pittsburgh Pirates non-tendered 2015 starting first baseman Pedro Alvarez on December 2, 2015. The club signed current first base John Jaso on December 23, 2015. St. Louis Cardinals first baseman Matt Adams had been a solid player from 2013-2014 before having down year last season, in part because of injury. Adams is back and having a career year, but how does he shake up compared to Jaso?

John Jaso v Matt Adams

John Jaso has started off his Pirates’ career hitting .280/.352/.398 with a .750 OPS (104 OPS+), very respectable numbers, especially batting first. Adams is off to a .299/.347/.535 with an .882 OPS (134 OPS+). Jaso has 20 RBIs in 237 plate appearances compared to Adams’ 33 RBIs in 170 plate appearances. However, RBIs are a statistic that is a product of situation – Jaso has 52 plate appearances with runners in scoring position and Adams has 49 plate appearances, in this case, it shows how productive Adams has been with RISP – and OPS is skewed heavily toward power hitters.

To start, lets take a true value of each players contribution to runs created, using OBP and SLG, the two numbers that make up OPS. To make an accurate assessment, OBP has to be multiplied by 1.8 because in terms of run scoring, OBP is 1.8 times more valuable than slugging. To see which player has been more valuable to run scoring this season – only using these two variables instead of OPS – the formula becomes(1.8(Jaso OBP-Adams OBP))+(Jaso SLG-Adams SLG). Adams will come out on top, as the difference in OBP is minimal and the difference in SLG is large, but how large the difference is, is the question.

(1.80(.352-.347))+(.398-.535)
0.009+(-.137)
-0.128

Matt Adams, when using OBP and SLG as the variables, is clearly the favorite towards run scoring, and the 0.128 difference between the two is less than the 0.132 difference in OPS, so the difference when adjusting is 0.004 points lower. But there are far more variables in baseball than just how a player gets on base and how much power a player has. It’s also important to look at when a player’s valuable moments have occurred to help them win. It’s also important to look at defense and other advanced numbers.

Run Expectancy, or RE24, is described by Fangraphs as:

Mandatory Credit: Charles LeClaire-USA TODAY Sports /

"On the hitting side, RE24 is a measure of how well hitters are capitalizing on their opportunities while also not assigning extra credit (like RBI) to hitters who happen to come to the plate with men on base very often."

It’s important to note, that RE24 is not based off of the context of the score or the inning. Jaso comes in with a RE24 of 9.30 and Matt Adams has a 12.50 RE24. Adams has capitalized on his chances more so than Jaso.

A more simple approach could be to look at their runners in scoring position splits. John Jaso is hitting .286/.392/.452 and a 0.845 OPS with RISP compared to the .409/.449/.682 and a 1.131 OPS for Adams, a difference between the two players OPS of 0.286. When adjusting the OPS values to calculate the extra value of OBP, the difference for Adams comes out as a +0.3326, an even higher difference in OPS for Adams with RISP.

Another way to look at the players is through their wOBA and wRC+ values. Fangraphs describes wOBA as:

"Weighted On-Base Average combines all the different aspects of hitting into one metric, weighting each of them in proportion to their actual run value. While batting average, on-base percentage, and slugging percentage fall short in accuracy and scope, wOBA measures and captures offensive value more accurately and comprehensively."

The wOBA formula for the current 2016 season is:

wOBA = (0.689×uBB + 0.719×HBP + 0.879×1B + 1.246×2B + 1.577×3B +
2.031×HR) / (AB + BB – IBB + SF + HBP)

John Jaso has a wOBA of .329 and Adams a .372. Jaso has been average and Adams has been great. Another large edge for Adams. Even in wRC+ Adams has the edge, the description from Fangraphs is as followed:

"Weighted Runs Created (wRC) is an improved version of Bill James’ Runs Created (RC) statistic, which attempted to quantify a player’s total offensive value and measure it by runs. In Runs Created, instead of looking at a player’s line and listing out all the details (e.g. 23 2B, 15 HR, 55 BB, 110 K, 19 SB, 5 CS), the information is synthesized into one metric in order to say, “Player X was worth 24 runs to his team last year.” While the idea was sound, James’ formula has since been superseded by Tom Tango’s wRC , which is based on Weighted On-Base Average (wOBA)Similar to OPS+, Weighted Runs Created Plus (wRC+) measures how a player’s wRC compares with league average after controlling for park effects. League average for position players is 100, and every point above 100 is a percentage point above league average."

John Jaso has a 109 wRC+ making him nine percent better than league average. Adams comes in today with a 136 wRC+ making him 36 percent better than league average. Adams has been 27 percent better than Jaso in terms of run creation.

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Adams has been better than Jaso using these numbers, even in WAR with his 0.9 fWAR compared to Jaso’s 0.4 fWAR. With the glove Adams has the slight edge, as his 1 defensive runs saved is better than the -1 from Jaso. Jaso has the edge in UZR/150, as he is at 3.0 compared to Adams’ -0.5, showing Jaso has had slightly better range this year for 150 attempts. Jaso also has the better fielding percentage, 0.993 to 0.986, and has done so in more innings – 409.2 to 322, an 87.2 difference for Jaso to Adams.

All across the board, Adams has the edge over Jaso, but what about in the win probability each has added. Win Probability Added (WPA) captures the differences in terms of value of situation, such as a blowout home run compared to a home run to give the team a one run lead, and Fangraphs describes it as such:

"Win Probability Added (WPA) captures the change in Win Expectancy from one plate appearance to the next and credits or debits the player based on how much their action increased their team’s odds of winning. Most sabermetric statistics are context neutral — they do not consider the situation of a particular event or how some plays are more crucial to a win than others. While wOBA rates all home runs as equal, we know intuitively that a home run in the third inning of a blowout is less important to that win than a home run in the bottom of the ninth inning of a close game. WPA captures this difference."

John Jaso has managed to have a WPA of 1.08, where as Adams has a WPA of 1.11. The problem with WPA is the amount of opportunities. To have higher WPA numbers, you have to be presented with more opportunities, it’s another example of product of situations. When taking each player’s WPA and dividing it by the league index (WPA/LI), we are able to compare the players. Adams once again comes out on top with a 0.99 WPA/LI to Jaso’s 0.53.

In conclusion, the Cardinals have the advantage at first base over the Pirates, a trend that has gone on for many of years, even with Jaso performing well.

Tomorrow will round out John Jaso compared to National League Central first baseman with a look at Jaso compared to Chicago Cubs first baseman Anthony Rizzo.

*Numbers as of games before Tuesday games and from FanGraphs

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