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Stan Wawrinka was all power Friday night against Andy Murray at the Barclays ATP World Tour Finals.

Brain Game: Wawrinka's Power Game

Learn how Stan Wawrinka booked his spot in the semi-finals with victory over Andy Murray

Power thumped precision. Stan Wawrinka defeated Andy Murray 7-6(4), 6-4 at the Barclays ATP World Tour Finals on Friday night, primarily by pulverizing the ball with every single shot in the book.

Wawrinka punched his place into Saturday's semi-final against Roger Federer with a stunning display of power tennis, especially sending a message at the start of the match with his ferocious groundstrokes.

After the first three games, Wawrinka’s average forehand speed was a high-octane 80 miles per hour (mph), 11 mph faster than Murray’s average of 69 mph. Wawrinka pole-axed everything he could lay his hands on, setting the evening’s terms of engagement without saying a word.

Wawrinka was also getting after his backhand as well, averaging a substantial 75 mph, to Murray’s 68 mph. Wawrinka’s power tennis created sensational winners, and the atmosphere of a heavy-weight fight at the packed O2 arena.

The crowd were instantly engaged with Wawrinka’s angry groundstrokes, and the place buzzed with electricity and massive applause for both players as they stared each other down with raw power.

Murray responded to the early onslaught by upping his speed, effectively matching Wawrinka blow-for-blow. After seven games, Murray had increased his average forehand speed from 69 mph to 74 mph, taking the sting out Wawrinka’s forehand, which dropped from an average of 80 mph to 75 mph.

Wawrinka broke for a 5-3 lead in the first set, but was broken right back, and skipped his racquet from around the baseline to his chair in disgust at not putting Murray away.

There are several key elements to Wawrinka’s stunning power, including coiling his upper body so well against his lower body, pure racket-head acceleration, exceptional balance, and a conviction to make the ball feel like it’s made out of lead when the opponent tries to hit it back.

Half way through the second set, Wawrinka increased the power level again to race to the finish line. His forehand speed had risen to 77 mph, while Murray’s had slightly dropped back to 71 mph.

Wawrinka found the most separation in speed going backhand-to-backhand, averaging 73 mph to Murray’s 65 mph at the half-way point of the second set.

Wawrinka hit 73 per cent of his backhands cross court for the match, landing 14 per cent in the service box, 28 per cent closer to the back half of the court between the service line and the baseline, and 58 per cent around mid-court, closer to the service line than the baseline.

With Wawrinka serving for the match at 5-4, he quickly fell behind 0/30, but a raking 95 mph cross court forehand was simply too big for Murray to handle, dumping it in net on full defence.

Wawrinka would escape a 15/40 hole at 5-4, and with the score at deuce, Murray destroyed his racket after Wawrinka put away an overhead to move to match point.

The pressure cooker that the power created simply boiled over, and Wawrinka would win the match a few points later when Murray a missed a cross court backhand wide. Overall, Wawrinka hit 27 winners to Murray’s 22, with raw power being the primary weapon of choice.

Wawrinka Serving

It was not a good day serving for the Swiss, only making a lowly 45 per cent of his first serves, but when they did go in, his accuracy close to the lines was impeccable.

Infosys Match Insights showed that Wawrinka hit 87 per cent of his first serves within two feet of the edge of the service box.

Serving in the deuce court, Wawrinka landed 10/10 in the two-foot target close to the center line, and 3/5 sliding out wide. In the Ad court, Wawrinka pin-pointed 9/10 down the middle close to the line, and 5/9 kicking out wide to Murray’s backhand.

Wawrinka has always been a player that does not necessarily make the most first serves, but wins a substantial amount (75 per cent against Murray) when they do go in.

Wawrinka won a very healthy 59 per cent of his second serves (Murray 48 per cent), again using pace as a key weapon. Wawrinka's fastest second serve for the match was 111 mph, 14 mph faster than Murray’s 97 mph.

On the slow end of the scale on second serves, Wawrinka only dipped down to 90 mph, while Murray clocked a very pedestrian 77 mph.

Wawrinka’s power game will be on display this evening against Federer, and the same bruising tactics will surely be employed.

Craig O'Shannessy uses extensive tagging, metrics and formulas to uncover the patterns and percentages behind the game. Read more at www.braingametennis.com.