Detroit Tigers pitcher Justin Verlander enters Sunday’s series finale against the Boston Red Sox with a 12-7 record and a 3.44 ERA, but it takes a deeper look at the numbers to illustrate just how good he has been this season.

Ask Tigers manager Brad Ausmus and he’ll likely harken back to one particular game last season -- a winning eight-inning effort against the Tampa Bay Rays on July 29 -- as the moment he felt the former AL Cy Young winner was back. But the 33-year-old Verlander has made steady progress this season as well to return to ace form.

Justin Verlander this season April-June Since W-L 7-6 5-1 ERA 4.30 2.01 WHIP 1.13 0.91 Opp BA .233 .181 BA with RISP .236 .143

Here is a look, fueled by research from ESPN Stats and Information, at how he has done just that:

1. Verlander has improved in almost every statistical category since the beginning of July. After posting a 7-6 record from the start of the season through the end of June, he has gone 5-1 since. Beyond that, his numbers reflect how much more efficient he has become during that span. The chart to the right shows how he has fared since the first three months of this campaign.

Percentage of pitches thrown April-June Since Fastball 57.9 53.7 Changeup 9.7 10.0 Curveball 14.8 17.1 Slider 17.6 19.2

2. He’s mixing his pitches more. The numbers are not dramatic, but they are worth noting: Verlander has been employing his fastball less (4.2 percent less, to be exact) and mixing in his secondary pitches more in his last nine outings. Particularly, he has shown more confidence in throwing both his curveball and his slider. Both pitches have been weapons for him all season long, with opponents hitting just .177 against his breaking balls (curve/slider), but they have proved even more potent over the past six weeks. Since the start of July, he has thrown his breaking balls more often (36.3 percent vs. 31.6 percent) and been more effective, with opponents hitting just .163 against them.

3. His velocity has increased. Verlander is not throwing the same type of heat he was earlier in his career, but he has repeatedly still demonstrated his ability to reach back deep into games and top out in the mid to high 90s. What’s more, his fastball velocity has increased since the first three months of the season. Verlander was throwing a 92.7 mph fastball on average through June. Since then he is up to 94 mph on average. Opponents posted a .267 batting average and .515 slugging percentage vs. Verlander's fastball from April through June. Since then, opponents have a .181 average and .295 slugging percentage vs. Verlander's fastball. Part of that is likely due to the uptick in velocity, though the fact that he is throwing his fastball less is also likely to be a factor. It’s not just his fastball, either. His overall pitch velocity has increased from 88.6 mph to 89.6 mph as well.

4. He is getting out of jams at a much higher rate. Since July 1, Verlander is tied for seventh in major league baseball with a .143 opponents' batting average with runners in scoring position. Compare that to the first three months of the season, when he was tied for 38th (.236), and it illustrates that Verlander is not only letting fewer runners on base, but that when they do get on base -- particularly on second and third -- he’s been able to attack batters at the plate and prevent further damage at a higher rate.

Verlander will try to continue his success against Boston when he squares off against Red Sox left-hander Henry Owens on Sunday. In his previous start against the Red Sox, a win on July 25 in Boston, Verlander surrendered just one run on five hits in six innings.

Jordan Burton of the ESPN Stats & Information group contributed to this article.