Ahead of the fourth round of the HSBC Sevens World Series in Las Vegas, we take a look back at the first three rounds of what can arguably be described as the most compelling and competitive Series yet.

Fans heading to the Sam Boyd Stadium this weekend for the USA Sevens, or watching any of the remaining six rounds, are in for a real sporting treat. And that isn't just a whimsical claim - the stats back it up.

So far this season a try has been scored every 74 seconds of game time!

Add to that, 68% of those tries are scored with no completed tackle or ruck/maul in the build-up and 42% from a passage of possession originating within the scoring side's own half.

All of that translates into fluid, end-to-end running rugby, but not a free-for-all. In fact, the contest for the ball has never been as ferocious in Rugby Sevens: 42% of tries are scored from a turnover in possession, with 78% of all restarts recorded as 'contestable'. In all, 22% of tackle, ruck and maul situations are being turned over.

The action has also been at its most competitive with 38% of the 135 matches played so far won by a margin of 10 points or less. The knock-out stages are even tighter on average, 43% of the matches won by 10 points of less.

Perhaps most interestingly for all Rugby fans is that the ball is in play for 53% of the time, or seven minutes and 24 seconds per 14-minute match - the highest percentage across all forms and competitions of Rugby Union.

Sevens World Series: Story so far

Round 1, Australia - In the opening round on Australia's Gold Coast the highest score was England's 54-7 defeat of Spain, but Simon Amor's side also recorded a 47-point victory against South Africa in the third place play-off. 

New Zealand went on to win the first round and they did so conceding just 24 points - 19 of which came in the final against the hosts. 

Round 2, Dubai - In the second and third rounds of the Series in Dubai and South Africa we saw South Africa make two finals, losing to Fiji in Dubai, before beating New Zealand in the final on home soil.

In Dubai, Fiji recorded their biggest ever victory against New Zealand, winning 44-0 by retaining possession for almost the entire match through superiority at the restart, and were on fire against South Africa

Round 3, South Africa - It was written in the stars a week later in the Nelson Mandela Bay Stadium, the Blitzbokke playing like men possessed to put a smile on the nation's face in sad and emotional circumstances and pay tribute to the late Nelson Mandela in the best possible way.

New Zealand lead the current standings heading into this weekend but by only two points from South Africa, and 10 ahead of Fiji. 

With three different Cup winners in the three tournaments so far, and with tactics needing to adjust for the ultra-narrow pitch at the Sam Boyd Stadium, it could well be four from four this weekend making the race for the overall Series even tighter....

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