17 IP, 5 H, 0 R, 22 K, 1 BB
The baseball observer will observe that those numbers can be characterized variously as "good" and "good, good" and "yes."
As for Cueto, he whiffed 12, walked none, spotted 71 of his 107 pitches for strikes and went the distance. Per the Baseball-Reference Play Index, it's just the 73rd time since 1914 (the back end of searchable data) that a pitcher has struck out 12 or more while walking none and twirling a complete-game shutout.
As for Cueto's path to dominating the Pirates, threw just about everything at them (source: Brooks Baseball) ...
As you can see, that's six different pitches on the day, five of them for a high strike percentage.
Not much has gone right for the Reds thus far in 2014, but a healthy and vintage Cueto at the front of the rotation is just what they need. He's been just that to date, and he's missing bats like never before.
As for Tanaka, let's just say the wipeout splitter was indeed working against the Cubs. In fact, per Brooks Tanaka threw 29 split-fingers on the day, and 22 of them went for strikes. Most impressively, Chicago hitters swung and missed at 10 of them. That pitch in tandem with heavy use of his sinker also helped Tanaka induce seven ground-outs.
Simply put, Tanaka has been tremendous over the first three starts of his MLB career. In 22 innings of work, he's given up six runs, struck out 28 against just two walks and notched a groundball percentage of 50.0. In other words, not many are balls are put in play against him, and half of those that are wind up on the ground.
Executive summary: On Wednesday, the aces of two likely contenders pitched exactly like aces.