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The Washington Nationals are currently 46-31 and sitting atop the National League East with an 8.5 game lead over the Mets. This success can be attributed to fantastic starts by several All-Stars such as Bryce Harper, Max Scherzer, Daniel Murphy, and Gio Gonzalez. Yes. The last player I listed was soon to be 33-year-old pitcher, Gio Gonzalez. He has been putting up All-Star numbers so far this season, pitching to a 7-2 record with a 2.87 ERA, but if you look deeper into the season that Gonzalez is having, it has been less than stellar to say the least.
This season, Gonzalez is striking out 8.52 batters per nine innings. This is actually a very solid number, as it ranks in the top 30 among qualified starting pitchers this season. However, it is the second lowest mark of his career and his lowest since 2010. Along with a lower strikeout rate, Gonzalez is walking hitters at an alarmingly high rate. His BB/9 this season is 4.04, which is his highest mark since 2011 and the seventh highest mark in the MLB among starting pitchers this season.
Gio Gonzalez is also giving up home runs at a very high rate. His 1.17 HR/9 this season is the second highest mark of his career behind the 1.28 home runs per nine innings that he allowed his rookie season. His home run to fly ball ratio is also up this year to 12.9%. The league average is roughly 10%, and you would expect Gonzalez to regress towards that number, but since he had a 12.5% HR/FB ratio over 177 innings last season, it is more likely to continue.
A very significant difference in Gio Gonzalez’s game this season compared to previous years is the change in fastball velocity. This year, according to Baseball Savant, his four-seam fastball is averaging at 90.56 mph. Just two years ago, in 2015, his fastball averaged at 92.53 mph. That is a 1.97 mph drop. According to Fangraphs, Gonzalez has the 13th slowest fastball in the majors among starting pitchers. His four-seam used to be right around league average in terms of velocity, but now he is far below that mark.
One stat that makes an appearance in many of my articles is BABIP, or batting average on balls in play. Gonzalez has a BABIP against him of .261, which is the 11th lowest number in the league. Although one aspect of BABIP is talent level, it is more likely that his low BABIP is caused by luck. As the season goes on, Gonzalez’s BABIP will likely elevate towards league average, which is .300, increasing his ERA as well.
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Right now, Gio Gonzalez does have a very impressive 2.87 ERA, but he has a FIP of 4.37. FIP stands for fielding independent pitching, which, according to Fangraphs, is “a measurement of a pitcher’s performance that strips out the role of defense, luck, and sequencing, making it a more stable indicator of how a pitcher actually performed over a given period of time than a runs allowed based statistic.” FIP is based on an ERA scale, so a 4.37 FIP is just like having a 4.37 ERA.
If a pitcher has a much higher FIP than ERA, it means that they are not pitching as well as their ERA suggests. Gio Gonzalez has the third largest negative difference between his ERA and FIP at -1.49. Although he has the seventh best ERA this year, his lofty FIP suggests that it may only be a mirage.
All of the statistics that I have laid out above suggest that Gio Gonzalez is not the pitcher that his ERA says he is. But how can a pitcher who seems to be pitching so poorly have such a low ERA?
The number one reason why Gio Gonzalez has been so successful this season when it looks like he may be declining as a pitcher is because of his LOB% (left on base percentage). Gonzalez has an outstanding LOB% of 85.7%, which is by far his career best and fourth in the majors. A high LOB% means that Gonzalez has stranded a lot of the runners that he has allowed to reach base, minimizing the amount of runs he has given up.
Although strikeout pitchers can have a higher LOB% than the league average, and Gonzalez strikes a lot of hitters out, a LOB% of 85.7% is unsustainable. That number will regress towards the league average of 72%, allowing more runs to score on him, which will increase his ERA.
These numbers suggest a major regression from Gio Gonzalez in the second half of the season, so if you own him in fantasy, now would be a good time to sell high on him.