The last time we saw something like this it was Rich Hill, signing by the A’s on the basis of 29 spectacular innings over 4 late season starts for the Red Sox. Hill’s sudden resurgence — he hadn’t really done much of anything for 8 years prior — was real and the A’s had plucked an ace out of thin air.
Of course there’s a reason front offices don’t generally make decisions based on 4 starts, or 30 at bats, or a handful of defensive plays. Small samples tend to zoom in too far to see the bigger picture of ebbs and flows, hot and cold, mirages often fueled by wishful thinking.