Fortunately for the St. Louis Cardinals, starting pitcher Lance Lynn has had a stretch of superb luck.

Here’s a stat for you: Lance Lynn is eighth in baseball with a 2.94 earned run average (ERA). That’s better than names like Luis Severino, Zack Greinke and even Cardinals ace Carlos Martinez.

Here’s another stat for you: Lance Lynn is 55th in baseball with a 4.71 fielding independent pitching (FIP). That’s out of 66 qualified pitchers.

Therein lies everything you need to know about Lynn’s 2017 season. Depending on which way you look, Lynn has either been one of the best or one of the worst pitchers in the majors.

The dichotomy is historic. Lynn is outperforming his FIP by 1.77 runs. Since 1896, there have been 8,890 qualified pitching seasons. Lynn’s mark is the third-highest of them all. By Tuesday night, he could pass 1981 Sammy Stewart (1.79) for the top spot. Gio Gonzalez (1.38) is the next-closest this season.

Where did this Lynn come from?

It’s difficult to understand how this happened. Lynn had a career 3.37 ERA and 3.36 FIP entering this year. Somehow, those two figures have managed to diverge to two extremes this summer.

One possible explanation could be that there’s a Coors Field effect of sorts going on. But that theory is discarded quickly by a glance at the splits: Lynn’s 2.87 ERA, 1.15 walks plus hits per inning pitched (WHIP) and 2.00 strikeout-to-walk ratio (K/BB) at home are matched by a 2.99 ERA, 1.17 WHIP and 2.08 K/BB on road.

How about splitting his season in two? Lynn has been arguably the most effective pitcher in MLB since July 9, posting a 1.77 ERA in 12 starts. Before that, he was rock-solid (3.87), but is there anything in his peripherals to suggest such a total transformation?

The answer is no and yes. Lynn’s actually been worse at the things over which he has the most control! His 22.8 strikeout rate (K%) has regressed to 15.7, while his 9.3 walk rate (BB%) has bumped up to 10.2. He’s been great at limiting hard contact all season, with a .225 batting average on balls in play pre-July 9 and a .237 since.

Lynn’s taken a bad extreme and turned it into a very good extreme.

This is where we discover the real reason Lynn has been so exceptional these past couple months. Lynn has allowed just four home runs since July 9, a swift reversal from his performance prior. In fact, he had allowed a home run in each of his four games prior to that one, including a four-home run bruising to begin the stretch.

Through July 4, 19.6 percent of Lynn’s fly balls were turning into home runs, a massive rate. If that was Lynn’s full-season mark, it would be tied for 64th out of 66 in the league. Since then, that rate has plummeted to 5.5. That alone would be first, and by no small margin: The top HR/FB% is Andrew Cashner’s 7.9.

The polarity is almost unbelievable, yet it’s single-handedly remodeled Lynn from a reliable pitcher to an elite one. Sure, he’s done his part to keep the ball in the park, upping his ground ball rate 5.2 percent and dropping his fly ball rate by 5.9. He’s also prevented runners from scoring by stranding more of them (79.1 left on base percentage to 86.5). But Lynn is essentially a pitcher with a below-average K% and BB% masquerading as a top starter because of extreme fly ball luck.

Almost certainly, Lynn’s homer rate was bound to come down in the second half. Similarly, his current suppressed rate is obviously unsustainable.

But it doesn’t matter now. Now, the Cardinals are locked into a playoff race, and Lynn has been a huge reason why (good thing they didn’t trade him). He has four more regular season starts before becoming a free agent. For him to make more than that, St. Louis might just have to hold on and pray the fly balls continue to avoid the stands.

Image Credit: Jeff Curry-USA TODAY Sports