Factor 1: It takes more pitches to complete a no-hitter than ever before.
This season, batters are making pitchers throw a record 3.93 pitches per
plate appearance, up from 3.89 last year, 3.83 in 2015 and 3.74 in the early
2000s. Outs take more pitches than hits, and strikeouts take more pitches
than other outs, and strikeouts are a bigger percentage of outs than they've
ever been. For that matter, walks (which take the most pitches of all) are
much more common than they've been in any season since 2000.
原因一:這個原因會比以前投出無安打比賽花更多用球數。這一季打者每個打席所花的
球數是3.93顆，比去年的3.89顆，2015年的3.83顆以及2000初期的3.74顆還要多。
出局所花的球數比擊出安打還要多，而投出三振比任何出局方式用球數都還要多
而三振占了比賽的大部分的出局數。而且，從2000開始四壞球變得更普遍。
If we look at all the games in which a team threw nine innings and allowed no
hits or one hit, the number of pitches required to get the 27 outs has been
steadily rising. In the 1990s, the median pitch count in these games was 114.
In the 2000s, it was 115, in the first half of this decade it was 117, and in
2016-2017 it was 120. This year, the median is 125 pitches. Most of those are
one-hitters, so knock off three or four pitches from those averages to
reflect one fewer batter, but the rise is real.
如果我們整季關注一支球隊在九局比賽內沒有安打或是一支安打，則用球數則會要抓27
個出局數而逐漸上升。在90年代，整場比賽的用球數的中位數是114顆。在00年代則是
115顆，在2005年時來到了117顆，到了16-17賽季是120顆。今年的用球數中位數是125顆
大部份這些是一安打比賽，所以可從平均值少算三或四球反映多出來的一個打者但有
上升是真的。
Factor 2: The occurrences of 120-pitch starts have gotten really rare. We all
know that teams are more sensitive about pitch counts, and that on average
pitchers get pulled from games earlier than ever. But it's not just on
average: On the extremes, in the very best starts, teams are far less likely
to let a pitcher go deep. Last season, 95 percent of starters were pulled at
110 pitches or fewer. Just seven years ago, the 95th percentile pitch count
was 117, and in 2000 it was 124