Caleb Martin has been the Miami Heat’s X-factor in the Eastern Conference finals

The Miami Heat trailed by 11 at the start of the second quarter and it appeared the Boston Celtics were on their way to evening the series. To that point, the Heat were having a hard time generating consistent looks against Boston’s double-big lineup, with Robert Williams III playing off Caleb Martin and denying Jimmy Butler and Bam Adebayo shots at the rim.

So the Heat turned Martin loose. Heat coach Erik Spoelstra dialed up plays to exploit Williams’ drop coverage and challenged Martin to take advantage of the space being given to him. So two minutes into the second quarter, Martin sets a screen for Kyle Lowry, who drags Jayson Tatum and Williams with him to the middle of the floor. Lowry kicks it out to a popping Martin and Williams scrambles to close out. Martin uses a left-to-right crossover to get Williams to turn his body, gets to his right hand and finishes through contact.

It was the first of Martin’s 12 points in the second quarter to help lift Miami back into the game and, eventually, beat the Celtics, 111-105, and take a 2-0 lead in the Eastern Conference finals.

The Celtics deployed a similar strategy in the conference finals last season, with Williams helping off PJ Tucker. Williams when healthy was a series-changer for the Celtics, blunting the impact of Miami’s pick-and-roll game and specifically made things difficult for Adebayo to get to the rim. Tucker, a limited offensive player, could only do so much in the space Williams gave him. When his corner 3-point shot went cold, so did Miami’s offense.

Martin is not Tucker. He’s a much more dynamic offensive player, capable of attacking that space with hard dribbles and athletic finishes at the basket. He’s developed into a knock-down 3-point shooter when given space. In that second quarter, he drained two 3-pointers from the right wing. As Williams closed out on him more, Martin attacked those close outs and got to the basket.

To counter, the Celtics went small in the second half, starting guard Derrick White in place of Williams. It was Celtics coach Joe Mazulla admitting that they cannot treat Martin, nor Miami’s offense, that way. They went back to switching on defense, Butler and Adebayo got to hunt mismatches and Miami’s offense opened up. Martin finished with 25 points. Butler (27 points) and Adebayo (22) took over down the stretch.

This was the vision the Heat had for Martin and their offense. After getting bogged down in last year’s conference finals, coming within a shot of advancing only because of Butler’s heroics and a late Celtics collapse, Spoelstra knew he needed to diversify the offense. Martin’s development has been a big part of that, and his performance in these conference finals have helped set the tone for the series and give the Heat a 2-0 lead.

If the Celtics stick with the small-ball lineup to start Game 3 on Sunday, it’ll be interesting to see if Spoelstra swaps Martin in for Kevin Love. Spoelstra has been committed to bringing Martin off the bench since the All-Star break, but the Heat have already forced the Celtics to adjust.