Whereas last year it was a mystery to rival that of the Bermuda Triangle, not least because Yorkshire posted seven scores of 180 or more including an English record 260-4 against Northants, this time it was a rather more simple conundrum.
Yorkshire were not quite consistent enough in most departments, including batting at the death and bowling in the powerplay.
Ultimately, however, a side that had some serious talent at its disposal for much of the tournament – albeit England leg-spinner Adil Rashid for only three matches –should have been good enough to advance to the last eight, the minimum expectation from within and outside Emerald Headingley.
For the second time in five seasons, in fact, it was Notts who put paid to Yorkshire’s hopes on the final night of North Group action.
In 2014, they had won the last group game here by six wickets with four balls to spare to squeeze out a Yorkshire team who instead finished fifth, reaching a target of 201 thanks to 67 from Alex Hales and an unbeaten 35 from James Taylor from just 14 deliveries.
On this occasion, before a crowd of 10,559 on a cool and overcast evening, Hales again starred, producing the highest score of the match (71 not out) as Notts leapfrogged Yorkshire to clinch the fourth and final qualifying place in a match that both sides had to win to reach the last eight.
After Yorkshire scored an under-par 163-6, David Willey contributing 51 from 40 balls, Adam Lyth 44 from 36 and Kane Williamson 44 from 26, Notts showed why they are defending champions as they won with an over to spare, Hales’s 32nd fifty in the format – an innings that comprised 56 balls – being well-supported by Tom Moores (45 not out from 24) and Jake Libby (30 from 23) as the visitors secured a quarter-final at South Group winners Somerset at Taunton.
Yorkshire, who opted to bat on a bare-looking pitch, were unchanged following their seven-wicket win at bottom-club Northants the previous night.
Notts brought in off-spinner Matt Carter for his T20 debut at the expense of Billy Root, younger brother of England Test captain Joe.
Carter it was who began proceedings from the Kirkstall Lane end, Tom Kohler-Cadmore sweeping the first ball for four before getting a leading edge to the second and popping it up into the hands of Steven Mullaney at short mid-wicket.
That brought together Lyth and Willey, who, 24 hours earlier, had compiled 150 for the second wicket in the match at Northants, Yorkshire’s highest T20 stand.
Both looked in the mood again as Lyth lofted Luke Fletcher behind backward-point for six before Willey took 16 off Carter’s third over, including a mighty maximum over long-on as Yorkshire, after a ponderous start, reached 40-1 at the end of the six-over powerplay.
Lyth struck a second six over mid-wicket when Fletcher returned, but timing the ball never looked easy.
Both men rode their luck at times, with the ball several times falling short of in-rushing fielders, and Yorkshire’s increasing anxiety to find the boundary was evidenced when Willey threw the kitchen sink at one delivery from Dan Christian only for the bat to fly clean out of his hands towards short fine-leg.
Bat made impeccable contact with the ball later in the over, however, Yorkshire’s acting captain smearing Christian down the ground, pulling him for six and then lofting him away over long-on. However, the second-wicket pair were denied a second successive hundred stand when Lyth skied Mullaney to the wicketkeeper, ending the partnership at 92.
Willey fell soon after, hammering a pull off Fletcher to deep mid-wicket, where Hales did well to hold an instinctive catch.
Yorkshire were 110-3 after 15 overs, but Williamson displayed power and precision to take 20 off the 16th over, bowled by Samit Patel, which included three fours and a six over mid-wicket.
Gary Ballance was caught at deep mid-wicket off Ish Sodhi in the next over, and Jordan Thompson – promoted to No.6 –was bowled by the excellent Harry Gurney, Williamson run out off the final in a selfless attempt to pinch an extra run.
When Notts replied, Riki Wessels struck four boundaries of varying certainty before chopping on to Willey to leave them 25-1 at the end of the third.
Notts also rode their luck on occasions as they, too, struggled for fluency. But Hales and Libby added 73 for the second-wicket inside nine overs in sensible style before Libby was stumped advancing to Lyth.
Hales played within himself, expertly guiding the chase and adding an unbroken 71 with Moores, who won the match with successive sixes off Willey.