The contrasting fortunes of Mitchell Starc and Jeet Raval

Starc strikes the first blow (0:25)

Mitchell Starc dismissed Jeet Raval in the seventh over as New Zealand fought for survival (0:25)

Test cricket is a game of great contrasts. Both macro and micro. In Perth, there has been the contrast between the overall fortunes of Australia and New Zealand which finished with a crushing victory for the home side. Within that the small moments that encapsulate the bigger picture.

Mitchell Starc is currently in the sort of form where little is going wrong. Jeet Raval is in the sort of form where little is going right. It came head-to-head in the opening session of the fourth day after New Zealand had been set 468.

Raval, playing his 23rd Test, is in the midst of a career slump and Starc is a Test bowler reborn after the early-season tweaks on his action that has brought consistency to his wicket-taking threat.

"Last Test of your career," Starc chirped to Raval as the left hander clung unconvincingly to the crease. A couple of balls later, after hanging on for 20 deliveries, Raval jabbed at a short-of-a-length delivery and offered a simple catch to point. He walked off with scores of 1 and 1 in the Test, taking his tally to his last nine innings - since his maiden hundred against Bangladesh in March - to 85 runs at 9.44.

For Starc it was his sixth wicket of the match. He would finish with 9 for 97 and the Man of the Match award, taking his Test haul this season to 23 wickets at 14.56 from three matches. With two Tests remaining he has every chance of making it his best summer ever - currently the mark is the 28 wickets he claimed in six matches of the 2016-17 season. He is living up the words on wrist band which reminds him to "f*** it, bowl fast."

"I'm finding less can go wrong when I'm more compact and having that ball on my back hip," he said after the second day's play. "There was a big conscious effort to be more economical as a group through the Ashes so taking a little bit out of that, but also the technical changes have helped me not sacrifice any pace but be more consistent."

Tim Paine was a delighted captain. "He's bowling really well, he's got new a theory, attitude to bowling which we've all seen on his wrist and it's work for him," he said. "I think his simple slogan is one thing but he's also worked very, very hard away from the cameras and refined his action a little bit which is giving him slightly better control. He deserves everything he's getting at the moment."

In contrast, New Zealand have a significant problem with Raval. They have invested considerable time and he was given backing when he struggled in the recent England series. There was justification in that. He scored six half-centuries in his first nine Tests before hitting the wall against England and Pakistan in 2018, but the maiden hundred in Hamilton was a weight off his shoulders. Now they must decide what do for the rest of this series. Kane Williamson is a wonderful batsman, and it's the lot of the No. 3 to often have to bat early, but it would aid New Zealand's cause if it wasn't so early.

"I suppose Jeet is like every other batsman in the world and that's that they want more and more runs and you always have good days and bad days," Williamson said. "These are some hard lessons for him and great experiences as well."

They have two days of match practice against a Victoria XI in Melbourne before the Boxing Day Test which is a chance to build some confidence. There is not a natural replacement in the squad with Tom Blundell, the reserve wicketkeeper, the spare batsman on the tour. He scored a century on Test debut, against West Indies in 2017, when standing in for BJ Watling but only played one further Test.

However, he is highly rated as a batsman - it was the deciding factor that earned him a spot at the World Cup - so he could come in a specialist batsman. Opening is unlikely, though, so there would need to be a reshuffle; a promotion for Henry Nicholls, who has opened in ODIs, would appear the only realistic option although Watling began his career as opener. But keeping and opening would be a tall order. That is all for New Zealand to ponder.

It was Watling's wicket, gloving down the leg side off Starc, the over after Colin de Grandhomme departed, that ensured Australia would earn a much-needed extra day off to rest the weary bodies of a bowling attack that did an outstanding job in the absence of Josh Hazlewood. They have to decide who will replace Hazlewood but have plenty of options. New Zealand have to decide about Raval's immediate future and there are far fewer directions for them to turn.