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The All-Star break is less than a month away and the chaos of the trade deadline is only five weeks away. I know it feels like the 2021 MLB season is just getting started, but we're in the thick of it now. Teams are coming up on their 81st game and soon the postseason races will intensify. I can't wait.

Our weekly series examining various trends across the league continues with a look at a pitcher with a new pitch, a great hitter's under-the-radar improvement, and a historic losing streak. Last week we examined Matt Olson's declining strikeout rate, Andrew Benintendi's burgeoning power, and Tarik Skubal's new old changeup.

Stroman's new pitch

Steve Cohen's Mets occupy first place in the NL East and not because of their offense. The Mets are averaging only 3.62 runs per game, second fewest in baseball, and they've scored five or more runs only 20 times in 68 games. That is easily the fewest in baseball. Despite the names on the roster, the Mets have been a weak offensive club in 2021.

The pitching, however, has been dynamite. The Mets have a team 3.11 ERA, second lowest in baseball, and they've allowed only 3.38 runs per game. That's the fewest in baseball. A greatly improved team defense is certainly part of that. The Mets were among the worst teams in baseball with minus-21 defensive runs saved last year. This season they're among the best at plus-28.

Right-hander Marcus Stroman is a significant component of the dynamite pitching staff. Stroman opted out of the 2020 season amid the pandemic, and has returned to pitch at an ace-level this season. A hip issue forced him out of Tuesday night's game after one inning, which is a bummer, but Stroman has a 2.32 ERA in 15 starts and 85 1/3 innings this season.

Throughout his career Stroman has succeeded with a deep arsenal that generates ground balls aplenty. He throws sinkers and cutters, sliders and curveballs, and every so often a changeup. This season, he's added a new splitter (technically it's a split-changeup grip) thanks to teammate Robert Gsellman, who taught him the pitch when they rehabbed injuries together last year.'s Anthony DiComo had the story in March:

In two innings, Stroman threw more than a half-dozen split changeups -- a pitch he learned from Robert Gsellman when both were rehabbing injuries in Brooklyn last summer. The pitch gives Stroman, who has generally relied on fastballs, sinkers and sliders throughout his career, an added dimension to his repertoire.

"Man, I love it," Stroman said. "That's a new pitch for me. I'm still getting comfortable with it, but to see the results today, it's extremely encouraging."

Already Stroman has thrown more split-changeups this season (172 in 85 1/3 innings) than changeups during the 2019 season (162 in 184 1/3 innings). He's gaining confidence in the pitch too. Stroman is using the split-changeup more and more as we get deeper into the season:

Marcus Stroman loves his new split-changeup. Brooks Baseball

The pitch has been very effective too. Opponents are hitting only .182 with a .250 slugging percentage against the split-change, and they're missing with 40.0 percent of their swings. The MLB averages for splitters and changeups are a .228 batting average and a .368 slugging percentage, with misses on 31.0 percent of swings. The pitch is already well-above-average.

In this era of huge strikeout totals, Stroman is an outlier because his strikeout rate is roughly league average, yet he gets a lot of ground balls and a lot of easy pop-ups. His pitches work together in a way that get him a first or second pitch ground out seemingly every inning, allowing Stroman to average over six innings per start (prior to Tuesday's injury-shortened one-inning start) despite not throwing more than 98 pitches in a game yet this year.

The split-changeup fits well with his sinker and cutter and gives Stroman yet another weapon. A weapon he feels confident in, and that part is important. A five-pitch pitcher isn't really a five-pitch pitcher if he doesn't have confidence in his fifth pitch. Stroman seems to love the splitter, and now he can ambush hitters even more with a deep arsenal of pitches that move all over the place.

"You never know until you throw it against hitters," Stroman told DiComo in spring training. "It can feel filthy, it can feel nasty, it can feel like the best pitch ever. But until you actually get out there and throw it in a game, and see how hitters react to it, I feel like you can't actually consider that pitch a weapon ... I feel like it's a weapon."

Guerrero's under-the-radar improvement

Vladimir Guerrero Jr.'s breakout season has arrived. The Blue Jays wunderkind has authored a .340/.441/.668 batting line through 71 games and leads baseball with 4.1 FanGraphs WAR. Guerrero is as talented as anyone in the game, and yet he needed a good 700 plate appearances to find his footing at the big-league level. Good reminder that development is not linear.

Guerrero's improved plate discipline (which was already good to start with) and launch angle have fueled his breakout, but there is another aspect of his game that has improved immensely: base-running. To be sure, Vlad Jr. is no speedster, but he's gone from a well-below-average runner (a baseclogger in old school baseball jargon) to a solid contributor.

Here are some before and after numbers:


Extra-base taken rate

35 percent

38 percent

Sprint speed

25.8 ft/s

27.0 ft/s

FanGraphs baserunning

minus-7.5 runs

plus-0.3 runs

The MLB average sprint speed is 27 feet per second, so Guerrero is an average runner now, and he's taking the extra base (first to third on a single, etc.) a little more often. FanGraphs' all-encompassing base-running stat covers everything from stealing bases to advancing on ground balls to moving up on wild pitches, and Guerrero had gone from comfortably below-average to average.

Going from horrible to just average is a significant improvement, and a lot of this can be explained by simple experience. Guerrero is in his third year as a big leaguer now and he's growing more comfortable and more confident. The same way a hitter or a pitcher can get better with experience, a base-runner can as well. That's part of it.

Also, Guerrero dropped over 40 pounds over the winter, and said he feels "quicker, strong, and more athletic." Most spring training "best shape of his life" stories are nothing. Just stories to pass the time. In Guerrero's case, the weight loss is noticeable, and yes, lose that much weight and you're going to be a better runner. The weight loss has undoubtedly contributed to his base-running.

Guerrero is and always will be a bat-first player. He is a generational talent at the plate, and you'll live with any defensive and base-running shortcomings to get that bat. In this case though, Guerrero has improved his base-running. He's not a game-changer on the bases, but he's not longer actively hurting his team with his base-running either. There's real value added.

Anatomy of a 17-game losing streak

Monday night, the Diamondbacks snapped a miserable 17-game losing streak that dated back to June 2. Their record 23-game road losing streak lives on, but the 17-game overall losing streak is over. At one point Arizona was 15-13 with a plus-6 run differential. Now they're on pace to lose over 115 games. Going 6-41 -- 6-41! -- in your last 47 games will do that. It's the worst 47-game stretch since at least 1936. 

The 17-game losing streak was baseball's longest since the 2005 Royals lost 19 straight games. How does a team lose 17 straight games? Like this:

Injuries: No one likes to use injuries as an excuse but they are an excuse, at least to some extent. The D-Backs have been without four of their top five starting pitchers the last few weeks. Madison Bumgarner and Luke Weaver are out with shoulder injuries, Taylor Widener is out with a groin injury, and Zac Gallen returned from an elbow injury just last week. Hard to replace four starters at once.

Arizona used seven different starting pitchers during the 17-game losing streak: Matt Peacock (four starts), Jon Duplantier (three), Merrill Kelly (three), Caleb Smith (three), Alex Young (two), Bumgarner (one), and Gallen (one). Bumgarner's lone start was his final start before the shoulder injury, and Gallen's lone start was essentially a rehab start following the elbow injury.

In the 17 games, those seven starters combined to pitch to an 8.22 ERA and averaged only 3.9 innings per start. Only twice in the 17 games did a starter complete six innings (Kelly and Smith once each), and seven times the starter failed to throw more than three innings. They had more starts with at least five runs allowed (four) than starts with fewer than three runs allowed (two).

It's difficult to win when your rotation constantly puts you in an early hole and your bullpen has to soak up innings. The injuries have forced Arizona to dip beyond their usual pitching reserves, and lean on guys who were expected to be no higher than eighth or ninth (or tenth) on the depth chart. Injuries are not the reason the D-Backs lost 17 straight, but they certainly contributed.

Coin-flip games: In only six of the 17 games did the D-Backs actually hold a lead, though on five occasions they were tied in the seventh inning or later. Obviously they blew all six leads and lost those games that were tied in the late innings. 

The lowest point of the losing streak came on June 15, when Arizona blew an early 7-0 lead against the Giants. They were up 7-0 in the second inning, but San Francisco chipped away and came back to win on Mike Yastrzemski's eighth inning go-ahead grand slam. That is about as painful as losses get.

The 17-game losing streak did not feature many blowouts. Five times the D-Backs lost by one run and only six times did they lose by more than three runs. They were in the majority of those 17 games, which makes it all the more gut-wrenching. It's one thing to go to the park and get blown out every night. It's another to battle and still keep coming up short.

Some better bullpen work and a few more favorable bounces in close games and the D-Backs could've been what, 7-10 in the 17 games? Maybe even 8-9 or 9-8? It's better to be lucky than good, but you have to be good too, and the D-Backs are the epitome of a team that finds a way to lose rather than a team that finds a way to pull out a win.

Offensive woes: Not surprisingly, Arizona was the worst hitting team in baseball during the 17-game losing streak, authoring a .216/.275/.324 batting line overall. That was approximately 34 percent below average once adjusted for ballpark and the league run-scoring environment. Some individual hitters during the 17-game losing streak:

That's four everyday players going a combined 30 for 182 (.165) with two home runs in a 17-game span. Rough. Ketel Marte (.362/.413/.517) and David Peralta (.304/.372/.370) were Arizona's two best hitters in those 17 games, but two players don't make a lineup. As a team, Arizona hit .246/.295/.343 with runners in scoring position during the 17-game losing streak. 

The D-Backs fired hitting coach Darnell Coles and assistant hitting coach Eric Hinske on June 10, seven games into the 17-game losing streak, though that was never going to fix what ails the team. Coaches are often scapegoats and Arizona's problems run pretty deep. The offense has been weak all year, and especially so during so during the long losing skid.