Ahn Woo-jin (24, Kiwoom Heroes) cited lowering his fastball usage rate as one of the secrets to becoming the league ace last year.
Ahn Woo-jin, whom I recently met in Gocheok, said, “What Pitching Coaches Noh Byeong-oh and Song Young-young have said is important since last year, ‘If you start out easily (earn a count) with a breaking ball and then throw a fastball, won’t the power of the fastball be revived?” I also started to reduce the direct purchase rate little by little, and the results were good.”
Last year, An Woo-jin won the Golden Glove for the first time in his career as a pitcher with an average ERA of 2.11, 15 wins, 8 losses and 224 strikeouts in 196 innings in 30 games. What was most different from his previous years was his fastball rate. According to Statties, a Korean baseball statistics site, Ahn Woo-jin’s fastball usage rate peaked at 60.3% in 2020, then gradually decreased to 52.9% in 2021 and 43.1% in 2022.
His fastball velocity has steadily increased since his debut, unofficially inversely proportional to the record of 160 km per hour (official maximum velocity of 159.8 km). It is somewhat surprising when you recall that KBO pitchers often count the ball with a fastball. This is because it is likely to actively utilize the faster fastball.
However, Ahn Woo-jin said, “There is no one who can’t hit a fastball. Especially in the KBO league, I think there are many players who can hit a fastball better. Maybe that’s why I feel more comfortable after increasing the proportion of breaking balls.” When I am at a disadvantage, I think the opponent will aim for my fastball. At that time, if I throw a breaking ball, there is a high probability that the hitter will come out because the batter is definitely not aiming for it. In that case, I will take the count for free. “The advantage of counting with a breaking ball explained.
The slider, which has risen even more, is a great help in getting the ball count in place of the fastball. Ahn Woo-jin said, “It is definitely easier to catch strikes with just two types of sliders. In my case, the slider has the most similar throwing feel to a fastball, so it is the easiest and most comfortable pitch to count.”
Although unintentional메이저놀이터, this change of Ahn Woo-jin is in line with the recent major league trend. In the major leagues, the number of fastballs is increasing on average in the league, but the usage rate is gradually declining. Excluding 2020 (50.5%), which was a 60-game shortened game season based on the US statistical site Fan Graph, the overall direct ball possession rate in the major leagues is gradually decreasing from 57.7% in 2015 to 49.1% last year. 2015 was the year when Statcast was introduced to the major leagues, where every ball could be tracked.
This starts from the fact that the fastball is a surprisingly inefficient ball. Surprisingly, it is better to earn counts with a breaking ball that each player throws best, instead of a fastball with a high hit rate and low swing rate. And the slider is attracting attention as a breaking ball to replace the fastball. According to Fangraph, the slider use rate has steadily increased from 14.7% in 2015 to 21.8% in 2022.
Spencer Strider (25, Atlanta), who finished second in the National League rookie of the year last year, is one of the representative players. He struck out 202 batters in 131⅔ innings last year with only fastballs (67%) and sliders (28%). “I don’t want to throw a ball that’s unlikely to result in an out,” Strider told The Athletic last month. “,” said the trend.
Ahn Woo-jin also said, “I heard in an article that the major leagues don’t throw a lot of fastballs, but I think it’s helpful because I did that too. It’s not that I don’t throw fastballs too much. I guess,” he laughed.
Ahn Woo-jin explained that lowering the rate of fastball use also helps to save physical strength. He said, “There is no such thing as burden on the elbow by throwing a lot of sliders. Rather, it saves physically. Physical strength is much better,” he said. “Of course, you have to know how to throw a strike with a breaking ball. If that doesn’t work, it will be more difficult.”
A different approach is expected to serve his new goals as well. Ahn Woo-jin, who transformed into an inning eater last year, has been greedy for innings rather than strikeouts since spring camp this year. As of April 15, it is cruising with 3 consecutive quality starts (6 innings or more and 3 earned runs or less). His detailed record is also good with an earned run average of 0.47, 4 walks and 29 strikeouts in 19 innings. If the current performance continues, Ahn Woo-jin will break through 200 innings in 7 years as a domestic pitcher after Yang Hyeon-jong (35, KIA Tigers) 200⅓ innings in 2016.