Another night to get some sleep, but this time Grand decides to toss in a long interval, so when I get out there, I get to see first overflow. And, of course, Grand lets West Triplet have the first eruption opportunity so it can use the second eruption window.
The late day Grand seemed to be determined to ignore my recipe for when eruptions occur. Not only was it between the two windows, but Rift was still erupting. Not sure why I try any more.
Grotto, meanwhile, was in eruption when I first saw it in the morning, and was still erupting 5-1/2 hours later. It was still going when the late day Grand had finished, 12 hours after I'd first observed it. Might try to catch the post-marathon Giant event, if it's in daylight, just to see my Guru Geyser Gazing proven wrong.