How do the advanced stats grade the Red Sox rookie phenom?

Michael Chavis has long been a top prospect in Boston’s organization. Since his call-up, he has impressed many and has contributed to the team’s turn-around after an atrocious April. As he surpasses 100 at-bats, it is appropriate to take a deeper dive into the analytics to see how he has performed. This article can also serve as a brief introduction into sabermetrics, since we will be covering various statistics.

*Note: There are many other good advanced stats that are not covered in this article.

Standard Stats

Games Played: 27

Plate Appearances: 117

At-Bats: 101

29 Hits / 18 1B / 2 2B / 9 HR / 17 R / 24 RBI / 15 BB / 31 K / .287 AVG


Park-adjusted Hitting Metrics

Park-adjusted hitting metrics are a quick, easy stat that encompasses a variety of other stats to deliver a single metric for a player’s offensive contributions. These stats aim to quantify the offensive value of a hitter, isolated from external factors. In other words, how much offensive production is this hitter responsible for and how valuable is his performance? These raw stats are then adjusted to the difficulty of the ballpark. The general consensus is that these stats are the best measure of a player’s offensive contribution.

Some of you may know OPS+ (On-base Plus Slugging Percentage Plus) or the more refined wRC+ (weighted Runs Created Plus). Recently, Baseball Prospectus developed a new version of this stats called DRC+ (Deserved Runs Created Plus). It is mathematically proven to be more accurate, reliable, and predictable that its competitors. You can read more about the new stat here and how it performs better than the others.

In terms of interpreting these stats, they are scaled to 100 which equals the league average. So, as Baseball Prospectus writes, a player with a 150 DRC+ is 50% better than the league average; the higher the number the better the player. For more reference, FanGraphs writes that a wRC+ of 60 is awful, 75 is poor, 80 is below average, 100 is average, 115 is above average, 140 is great, and 160 is excellent. In 2018, Mookie Betts had a wRC+ of 185.

Michael Chavis:

126 DRC+

151 wRC+

150 OPS+

The first thing that stands out with these stats is the discrepancy between DRC+ and the others. According to wRC+ and OPS+, Chavis is having a phenomenal season and would be 24th in the majors according to wRC+. Despite this discrepancy, his DRC+ score is still very good, especially for a rookie. Chavis is tied for 38th in DRC+ which is very impressive.

His DRC+ is tied with Christian Vazquez for fourth best on the team, 1 point behind Mitch Moreland. He leads the team in wRC+ and OPS+.


Most fans are probably aware of WAR (Wins Above Replacement). In brief, it is an all-encompassing statistic that aims to explain how many wins a player would contribute over a replacement player. As FanGraphs explains, “If this player got injured and their team had to replace them with a freely available minor leaguer or a AAAA player from their bench, how much value would the team be losing?”

A player with a higher WAR has more value than a player with a lower WAR. However, WAR is a statistic that builds throughout the season, so references to a “good” or “bad” WAR won’t be applicable in May. We can, however, look at Chavis’ WAR relative to the roster – keep in mind he’s played less games.

WAR is calculated differently depending on the website. This is why we specify bWAR, fWAR, and BWARP. bWAR is calculated by baseball-reference, fWAR by FanGraphs, and BWARP by Baseball Prospectus.

Michael Chavis:

0.7 BWARP (7th among Red Sox hitters)

1.2 fWAR (5th)

1.2 bWAR (4th)

WAR is not the most useful stat until the season is complete; however, Chavis has managed to climb the team rankings despite playing significantly less games. It will be interesting to revisit WAR in October to see how he has fared with more games under his belt.


wOBA and OPS

On-base Plus Slugging (OPS) combines on-base percentage (OBP) with slugging percentage (SLG) and is the foundation of OPS+. Weighted On-Base Average (wOBA) can be found on FanGraphs and it is the basis of wRC+. In short, not all hits are created equal. wOBA aims to measure a player’s offensive value and it combines numerous statistics. For example, a homerun has more value than a single and this is reflected in wOBA’s formula. It is viewed as superior to OPS because OPS assumes that one percentage point of SLG has the same value as one percentage point of OBP.

wOBA scores change every year but here is a general rule of thumb: .290 is awful, .300 is poor, .310 is below average, .320 is average, .340 is above average, .370 is great, and .400 is excellent. You can read more about wOBA here. The rule of thumb for OPS is as follows: .570 is awful, .600 is poor, .710 is average, .800 is above average, .900 is great, and 1.000 is excellent. You can read more about OPS here.

Michael Chavis:

.403 wOBA

.959 OPS

Based on our rule of thumb for wOBA, Chavis is having an excellent offensive output. Likewise, his OPS scores very high and edges closer to “excellent” than “great.” It is easy to understand his high wRC+ and OPS+ scores after seeing this. Chavis is contributing significant value offensively.

Strikeout and Walk Percentages

Another stat which can be helpful to use is strikeout (K%) and walk percentages (BB%). While these are not the most valuable metrics in evaluating a player’s offensive production, they can demonstrate plate discipline and contact skills. These stats are generally a summary of the player and can show areas for them to improve at the plate. These stats are not park or league adjusted and it should be noted that today’s game is seeing a higher strikeout rate than before, especially with power hitters.

As a rule of thumb, FanGraphs posts the following:

Excellent – 10.0% (K%) / 15.0% (BB%)

Great – 12.5% (K%) / 12.5% (BB%)

Above Average – 16.0% (K%) / 10.0% (BB%)

Average – 20.0% (K%) / 8.0% (BB%)

Below Average – 22.0% (K%) / 7.0% (BB%)

Poor – 25.0% (K%) / 5.5% (BB%)

Awful – 27.5% (K%) / 4.0% (BB%)

Michael Chavis:

26.5% K%

12.8% BB%

Chavis is a power hitter so his poor strikeout rate is not very concerning. Furthermore, Chavis is getting walked at a great rate which further contributes to his offensive production. It appears he has good plate discipline, but like many power hitters, tends to strikeout often.


It is absolutely crucial to note that Chavis has a relatively small sample size, and thus, his statistics are very volatile. Since beginning this article a few days ago, his advanced stats have shifted significantly. This suggests that more at-bats are needed before we get a clear picture of what we have in Chavis. Based on this, it is likely that the rookie will regress over the course of the season. He is on a phenomenal pace which is extremely difficult to maintain – and even if he does regress, there is nothing wrong with that.

Chavis has provided way more than anticipated of him since his call-up, and he’s been a significant contributor to this Red Sox team. Furthermore, it should be discussed how excellent he’s been thus far. Based on the advanced metrics, Chavis is having a great year offensively. He is providing power while also finding ways to get on base.

While the park-adjusted metrics disagree on how great he has been, they nonetheless show a thriving player. So far, Michael Chavis has been a remarkable addition to the squad. Whether he can maintain his offensive production is not yet clear, but what is for certain is the fact that he should be absolutely in the rookie of the year discussion.

* Stats courtesy of Baseball Prospectus, FanGraphs, and Baseball-Reference