Referee Steve Walsh sends Brad Thorn to the sideline. Photo by Craig Baxter.

There has been an average of two referrals per Super 15 game under the new third-match-official laws, with most of those rulings relating to tries.

Data released by Sanzar showed that, up to round 10 of the competition, in the 61 games played there had been 122 calls referred to the TMO.

Under new trials introduced by the IRB this season, the TMO has far wider powers, including the ability to rule on foul play and going back two phases to rule on infringements when a try has been scored.

New Zealand Rugby Union high performance referees manager Rod Hill said referees had definitely noticed the increase in workload for the TMOs.

Hill said overall feedback in the trials had been positive. People wanted to see accuracy in the decisions so a fair outcome was reached.

Five was the highest number of referrals for any game - that had happened four times - and six matches had been played without any referrals.

Referrals to decide whether a try had been scored made up 75% of the calls to the TMO, with 90 tries allowed or disallowed by the television monitor.

Of those 90 try appeals, 48 were awarded and 42 were disallowed. With 28 of the 61 games decided by seven points or fewer, it was clear accuracy was important.

There have been 13 yellow cards handed out after referrals. The most infamous this season involved Highlanders second five-eighth Ma'a Nonu, who was sin-binned for a shoulder charge against Blues halfback Piri Weepu.

Referee Steve Walsh initially just warned Nonu but after a referral, Nonu went to cool his heels on the sideline for 10 minutes.

The referral system has had its critics, with some coaches saying it does not make decisions any clearer and there is still too much ambiguity in decisions made.

The connection between the referee on the field and the man in the stand has also been less than smooth at times but it was always going to take time to iron out any problems.

The average time of a referral is 82 seconds and that time may come down as everyone gets used to it, Hill said.

The IRB is due to make a decision next May on whether the trial will become permanent.