Two points about the Hamilton test will give Williamson something to store in his captaincy file.
First his declaration, leaving Pakistan 369 to win, with New Zealand having three overs bowling on the penultimate afternoon.
Williamson copped some flak from fans over the delay before the declaration.
The argument was that his adventurous predecessor Brendon McCullum would have pressed for runs to be scored faster through that fourth day, enabling an earlier declaration.
But Williamson, in his first series as skipper at home, wasn't about to offer any free assistance to Pakistan.
He knew they needed to be encouraged to look for the win which would have enabled them to keep their No 2 test ranking. It was a balancing act.
But New Zealand had fought well for their ascendant position and had every right to make the job challenging for Pakistan.
And let's not confuse Williamson with McCullum. He's finding his way in the captaincy game and you sense he wears a more conservative cloak than McCullum. He deserves to be cut some slack in that area, and after all New Zealand did win the series 2-0.
Williamson got caught short with two referrals yesterday, the first a complete hash when no one seemed to know what was going on, and it turned out to be one of the worst you'll see.
But what if somehow there had been a brushing of ball on glove by seamer Matt Henry against Azhar Ali in the morning session? Williamson would have looked silly had he eschewed a referral.
The second one for an lbw appeal against opener Sami Aslam before lunch, was timed out by umpire Simon Fry.
Williamson wasn't thoroughly convinced he'd got his timing wrong. But it's just another little reminder to get the questions in to the key decision makers close to the wicket quickly.
Next Williamson has Australia, a country where, led by their TV commentary team, they scrutinise the performance of visiting captains closely.
An ODI series is different from tests. Still, expect the way Williamson runs his ship to be closely monitored for any signs of weakness or indecision.
It will be another good experience for the new skipper.
And at least Williamson had more to savour from the test than his counterpart.
Stand-in skipper Azhar Ali, following the lead of regular skipper Misbah-ul-Haq in the first test, has been fined, along with his players, for a slow overrate during the test.
Pakistan were found to be five overs short of their target by match referee Richie Richardson.
Azhar was fined a total of 100 percent of his match fee, his players 50 percent.
The rate is assessed at 10 percent per late over, double for the captain.
