The Colorado Rockies looked like they’d never seen anything like Shōta Imanaga on Monday. To be fair to everyone involved (most of all, us, the interested but untethered observers), that’s how the Rockies look a lot of the time. They’re a disaster, and they’ve looked even worse so far this young season than they actually are—a heroic feat in underachievement. In fact, all of the league’s expected cellar dwellers have looked intent on digging themselves a sub-basement, so far. It’s an unfortunate set of blotches on whichever array of box scores you normally find most pleasing to peruse each morning.

In this one case, though, the Rockies had a legitimate excuse for their cluelessness. They really were up against an alien force, beyond their experience or their capacity to adapt. Imanaga was making his first big-league start, in very pitcher-friendly conditions, and he didn’t look like he needed any of the help Mother Nature offered. In six innings, he allowed just three Colorado baserunners: two sixth-inning singles and a loopy liner to third base that eluded the immensely eludable Christopher Morel for an error. He struck out nine helpless visitors.

The southpaw who has been thrust unexpectedly into the ace role on this Cubs staff (thanks to the injury that felled Justin Steele on Opening Day) probably won’t stump everyone as thoroughly as he did the Rockies in his first turn, but his success wasn’t smoke and mirrors. While he lacks even average velocity, Imanaga has a lowish release point and excellent rising action on his four-seamer, and he earned a lot of lazy fly balls and mishit fouls with it Monday, even as the Rockies seemed to sit on it, and even as he threw it over 60% of the time. One measurement of his vertical approach angle (VAA) had him at -4.1 degrees with the heater, on average. That’s markedly above-average, meaning that that heater was sailing through the zone much flatter than most hitters could get their bats, leading to unproductive contact.