It doesn't take an understanding of advanced analytics to see the trend line.
In 2008, Major League pitchers struck out 17.5 percent of batters they faced, a record. That record subsequently has been reset each season since and sat at 22.5 percent entering Thursday, nearly a full percentage point above 2017's rate.
Pitchers have higher velocity, better stuff and more thorough preparation than ever before, and batters seem to be swinging harder and aiming for the fences more.
This phenomenon makes it more amazing that the single-season, individual record for strikeout rate still stands. But for how much longer?
Two challengers have emerged in 2018, one of them likely a preseason favorite to be in this position, and one seen as a candidate to tap into his significant potential.
Through nine outings apiece -- somewhere between one-quarter and one-third of a full season for an MLB starter -- Max Scherzer of the Nationals and Gerrit Cole of the Astros sport strikeout rates above 40 percent. That puts Hall of Famer Pedro Martinez in their sights.
TOP 10 SEASONS BY STRIKEOUT RATE

1. Gerrit Cole: 40.8 percent (2018, HOU)
   
2. Max Scherzer: 40.4 percent (2018, WSH)
   
3. Pedro Martinez: 37.5 percent (1999, BOS)
   
4. Randy Johnson: 37.4 percent (2001, ARI)
   
5. Chris Sale: 36.2 percent (2017, BOS)
   
6. Chris Sale: 34.9 percent (2018, BOS)
   
7. Pedro Martinez: 34.8 percent (2000, BOS)
   
8. Randy Johnson: 34.7 percent (2000, ARI)
   
9. Max Scherzer: 34.4 percent (2017, WSH)
   10-T. Patrick Corbin: 34.3 percent (2018, ARI)
   10-T. Jose Fernandez: 34.3 percent (2016, MIA)
   Qualified pitchers only
   Martinez's K-rate of 37.5 percent for the 1999 Red Sox is the best ever produced by a qualified pitcher, edging out Randy Johnson's 37.4 percent for the 2001 D-backs. Another Boston ace, Chris Sale, ranks third after posting a 36.2 percent rate last season.
   It's difficult to overstate the enormity of Martinez's feat, which came as part of one of the greatest pitching seasons of all time -- along with his 2000 campaign. In 1999, Martinez was 27 years old, in his second year with the Red Sox and already had a Cy Young Award under his belt, for the '97 Expos.
   Martinez went 23-4 in 1999 with a 2.07 ERA (243 ERA+) across 213 1/3 innings, striking out 313 batters while walking just 37 and giving up a mere nine home runs. His 1.39 FIP remains easily the best by a pitcher since the Dead Ball Era. And keep in mind, this was in a season when the AL, as a whole, batted .275/.347/.439, and AL pitchers produced a 15.7 percent strikeout rate.

In other words, Martinez had a steeper hill to climb than pitchers in 2018 do. Nonetheless, his record remains a difficult target.
Scherzer goes into his start against the Dodgers tonight with a 40.4 percent strikeout rate, having piled up double-digit Ks six times this season, including 15 in 6 1/3 innings on May 6 against the Phillies.
Scherzer is no stranger to the strikeout. The three-time Cy Young Award winner has led the NL in that category in two straight seasons, and is one of just four pitchers to strike out 20 batters in a nine-inning game. His strikeout rate, which was 27.9 percent in his last season with the Tigers, has increased in each season since joining Washington in 2015. The 33-year-old is showing no signs of slowing down, coming at hitters with a snarling intensity, a high-spin four-seam fastball and an array of nasty secondary pitches.
Perhaps nothing bodes better for Scherzer's chances than the fact that he can go right at opponents and win. No MLB starter can touch his 31.2 percent whiff rate on pitches in the strike zone, or his 38.5 percent whiff rate on fastballs.

Cole, however, ranks second in both of those categories. When the No. 1 overall Draft pick (2011) was traded from the Pirates to the Astros in January, there was immediate speculation that Houston might be able to unlock another level of performance in the 27-year-old righty. But even the most hopeful optimist would have been hard-pressed to foresee Cole's early-season performance, which includes an MLB-best 40.8 percent strikeout rate.
While Cole threw 203 innings for Pittsburgh in 2017, he ranked 45th in MLB in ERA+ (101) among 75 pitchers who threw at least 150 innings. His 23.1 percent strikeout rate -- which roughly matched his career average -- ranked 25th.
Cole has indeed upped his breaking ball usage in Houston, from 29.5 percent curveballs and sliders to 39.3 percent. Yet it's his four-seamer that has been the true star, as he has raised his sights with it, peppering the top of the zone and above in Scherzer-like fashion. That has helped Cole strike out at least 11 batters five times, including 16 in a one-hitter at Arizona on May 4.

So what would Cole and Scherzer need to do the rest of the way to pass Pedro?
At this point, they have faced almost the same number of hitters and have almost the same number of strikeouts. Assuming they finish with an ambitious 900 batters faced -- basically the total Scherzer reached in 2015 and '16 -- they each would need to strike out roughly 36.5 percent of their remaining opponents to set the record.
In such a scenario, they would finish with 338 strikeouts, which would be the most since Johnson tallied an incredible 372 in 2001 (Only Sale last season and Clayton Kershaw in '15 have reached the 300-strikeout plateau since Johnson and D-backs teammate Curt Schilling both did it in '02). While that 36.5 percent rate is a good bit under Cole and Scherzer's current pace, it still is higher than anyone other than Martinez (1999) and Johnson (2001) have posted in a full season.
In other words, there is a long road ahead, one that requries good health. And even one or two starts in which the strikeout stuff is missing can throw a wrench in the chase. For context, in 1999 Martinez struck out at least 10 in 19 of his 29 starts and only three times finished with fewer K's than innings pitched.
Still, it's a good sign that both Cole and Scherzer are ahead of the pace Sale set last season, when he struck out 38.6 percent of opponents through nine starts, as well as Martinez's at the same point in 1999 (37.9 percent).
So strap in and get ready for a lot more whiffs -- and maybe even a new record.