After two brilliant victories in four days transformed the mood around England’s white-ball team as well as his own job security, Matthew Mott has suggested he should not be judged by results achieved under his control.

A dismal attempt to defend the 50-over World Cup in India led to speculation over the Australian’s future as coach, but after an unimpressive start to their tour of West Indies the sudden location of their mojo in the Caribbean seems to have shored up his position.

Related: England set up West Indies decider as Phil Salt leads way to record T20 score

“I’ve been around the game a long time and I know it’s like the share market, your stock goes up and down all the time,” Mott said.

“When you get into coaching you realise you shouldn’t take too much credit for the success and not too much blame for the failures, because essentially you’re there to try and improve individual players. That’s what we try to do as coaches. We try and set them up to perform as best they can and then, particularly in T20s, sometimes the results are out of your control.”

More than anything said by Mott, it was the prospect of chasing 223 to win the third Twenty20 in Grenada and keep the series alive that inspired the team, and forced them to adopt the thrillingly aggressive mentality that has brought them back-to-back victories to tie the series at 2-2 before the decider on Thursday.

“Things happen for a reason, and to free everyone up to be able to go, ‘Right, this is how we’re going to play,’ we’ll probably look back on that as being a pivotal moment for this team,” Mott said. “That’s now our blueprint. We’ve been searching for it, we’ve been talking about it, but now we’ve seen what it looks like.

“I think the overwhelming feeling was almost like: ‘If we keep playing like this we’re going to get the same results.’ So let’s change it up a bit. Let’s free ourselves up. Let’s fight fire with fire and go out there and play. That massive chase has ignited a flame within the group and it’s galvanised everyone.”

The team have also found a new figurehead in Phil Salt, who last Saturday became the fifth Englishman to score a T20 century, and on Tuesday the first to score two. Mott said Salt had previously been guilty of having only two settings, “hard and harder”, but has shown that he now has a more complete game. As a result, though the absent Jonny Bairstow could force his way back into the squad in time for the T20 World Cup in June, there is no longer a vacancy at the top of the order, with Salt’s case “undeniable”.

Mott said: “I’ve always thought he was an amazing player. I think he does stuff that not many people can do. You could see a different look in his eyes [on Tuesday], like: ‘Not only do I belong, but I’ve got this.’ To me, you don’t know what you’ve got until you’ve achieved it, and all of a sudden he’s away, his international career is flying.”

Salt had averaged 0.7 sixes in his 18 T20 innings before last Saturday, but has now scored 19 in his past two. The 27-year-old has since revealed he has been working specifically on increasing the power with which he hits the ball to improve his six-hitting. “I’ve been working in the gym the last few months, trying to put a couple of kilos on,” he said.

“I wanted to make myself stronger, quicker and bigger, basically. I’ve been eating a lot of calories. To get through 3,500 calories a day has been a bit of a job. My missus has been raging because the shopping bill has gone through the roof.”

In six months England return to the Caribbean for the T20 World Cup – fixtures are expected to be announced on Thursday – with the experience gained in this series giving them “a really good advantage”. Though Jofra Archer and Ben Stokes will play if fit, most of the squad for this series will be involved. “We are starting to see already that with a bit of belief and confidence they can achieve great things,” Mott said.

The England and Wales Cricket Board has named Ed Barney as its new performance director, taking him from a similar position with Great Britain Hockey. Barney previously worked in talent identification at the ECB between 2010 and 2013.