The Nats finished a modestly successful April with a mix of good and bad starting pitching, and mix of good and bad efforts from the bull pen. Here's a look at the starting rotation's effectiveness in April.
A valuable way to analyze a pitcher's command of the strike zone is to look at the Pitch F/X data, and compare opponents AVG and SLG in those zones. I used this same technique in February (Starting Rotation - Command of the Strike Zone), to predict the Nats starting rotation. For the record, it was Lannan, Marquis, Detwiler, Stammen, and Olsen.
How does it work?
To make sense of the Pitch F/X data, I broke the plate area into a 5×5 grid. I then placed each pitch into the appropriate zone based on it's location as it crossed the plate. The red box denotes the strike zone (the center 9 squares); the outer squares are balls. Remember the Pitch F/X data is from the umpire's perspective. Right handed batters stand to the left of the chart. I then plotted 3 charts for each pitcher. The left chart shows the percentage of pitches thrown in each area of the zone. The center chart is the opposing hitter's batting average by zone. The chart on the right is opposing hitters slugging percentage by zone. It is early in the season, and the sample size is small - these numbers will mean more as the year progresses.
John Lannan faced 132 batters, and threw 473 pitches in April.
Lannan threw 47% of his pitches in the strike zone. He did a good job of keeping the ball low. The real problem for Lannan in April was the opponents batting average on the low pitches. Opponents hit over .500 on pitches thrown below the zone. Those low pitches have historically been Lannan's bread and butter. In order to be effective, he needs to give up fewer hits at the bottom of the zone.
Jason Marquis faced 50 batters and threw 179 pitches in April.
Marquis only threw 30.7% of his pitches in the strike zone. Marquis was hit hard in every region, with opposing AVG greater than .500 and opposing SLG greater than 0.750 in multiple regions. In my NatsStats post "Marquis Pitch Speed Backs up DL Move", I showed how Marquis' fastball/sinker lost 2-3 MPH this year. Based on the obvious physical issues he has, these numbers don't mean much. Hopefully he can return to health and pitch like he did in 2009.
Livo! threw 393 pitches to 117 batters.
The crafty veteran threw 40% of his April pitches in the strike zone, but he did it on purpose. Look at the locations - he threw the ball high, low, in, and out. We don't see speeds on this chart, but he mixed speeds as well as he mixed location. Opposing batters really struggled from the middle of the strike zone down. The higher Livo left the pitch, the more success batters had. Give Mike Rizzo credit - he called this one. Rizzo said the eephus throwing ageless wonder was still a valuable major league starter who could eat innings. In April at least, he was right.
Craig Stammen faced 88 batters, and threw 319 pitches.
Stammen threw pitches in the strike zone almost 45% of the time. This is a few points higher than his 2009 rate. The most impressive thing about Stammen was this - 60% of the pitches he threw were outside of the strike zone, but he only gave up 4 walks. Batters also have a ridiculously low batting average in the areas outside of the strike zone. Opponents do have a high AVG and high SLG in the center of the plate - some of this came in his disastrous 2nd start against the Phillies. If Stammen makes the adjustment to live on the black, he will have a productive season.
Scott Olsen threw 330 pitches to 92 batters.
Scott Olsen threw pitches in the strike zone 51% of the time. Olsen displays many of the same pitching characteristics that we see with Craig Stammen. He keeps the ball low in the zone, and batters have poor AVG and SLG outside of the zone. Olsen also tends to get too many pitches near the center of the plate, and he pays the price. In his few outings in 2009, Olsen had the same issues - he gave up a lot of hits when he threw the ball in the center of the plate. One positive adjustment so far this year - batters have not had success when he throws the ball in the low center of the strike zone.
Luis Atilano faced 54 batters in April, and threw 184 pitches.
Atilano threw pitches in the strike zone 41% of the time. He has done a decent job spreading the ball around, and somehow managed to survive while throwing 9.2% of his pitches down the middle of the zone. He has really succeeded living in the bottom of the zone, where he has the lowest opposing AVG of the starting staff. He has been a breath of fresh air and a sure sign that the Nats are headed in the right direction. They now have enough depth to replace an ineffective/injured starter - something that could not be said in the last 5 years.
Garrett Mock threw 84 pitches to 19 batters in 3.1 innings of April work.
Nothing much can be said about Mock's partial outing in April. Mock had similar problems in 2009. We'll wait until (if?) he pitches again until we examine his work.
Summing up the Starters
Livan Hernandez and Luis Atilano had solid Aprils. They didn't do anything fancy, but they each made the best of their starts. Olsen and Stammen each had good starts and they each had bad starts - hopefully the good will outweigh the bad as the season progresses. Lannan, Marquis, and Mock all struggled in April. Marquis and Mock are on the DL. Lannan needs to get his control back. His 15 walks and 1.93 WHIP are uncharacteristic - the sooner he returns to his old ways the better.
Tomorrow we will look at the relievers...