The good the bad and the ugly: Rugby's league converts

Rugby league convert Marika Koroibete in action during his first Wallabies training session. Photo / Getty Images

NRL convert Marika Koroibete will make his rugby debut for a Wallaby XV on Friday.

AAP takes a look at the good, the bad and the ugly of league-union switches.

THE GOOD

Jason Robinson: Widely regarded as the best convert, with 166 tries in 300-plus games for Wigan after 51 rugby Tests for England including the 2003 World Cup triumph.

Israel Folau: The two-time John Eales medal winner is an undisputed success story and currently among the game's best.

Sonny Bill Williams: An incredible athlete who made an excellent transition, a World Cup winner, Super Rugby champion and dual-code superstar.

Wendell Sailor: Finished in poor circumstances but a success as the first of the big names at the start of the 2000s to switch.

He chalked up 13 tries in 37 Tests for the Wallabies.

Mat Rogers: 45 Tests as a versatile playmaker who excelled at fullback and inside centre and was also a handy goalkicker.

Lote Tuqiri: Arguably the biggest name to switch at the time - prior to the 2003 World Cup - he played 30 Tests before returning to the NRL.

Berrick Barnes: A schoolboy star, Barnes rejoined the 15-man game after two seasons at the Brisbane Broncos and went on to play 51 times for the Wallabies.

THE BAD

Cooper Vuna: Another accomplished NRL tryscorer - 35 tries in 54 games for Newcastle - he wasn't quite as prolific after the switch.

Represented Australia twice.

Karmichael Hunt: The jury is still out on his long-term value but the former Australian rugby league representative hasn't hit the same heights in his two seasons at the Reds.

Timana Tahu: Endured an injury-plagued two years with the Waratahs and a brief four-Test Wallaby career before rejoining the NRL with Parramatta.

THE UGLY

Sam Burgess: His time in rugby was ugly for a variety of reasons.

Burgess was shuffled from the forwards to the backs, became the preferred target of the English press and then the face of England's early World Cup exit.

Nathan Blacklock: Made just five appearances - scoring two tries - in a very short stint with the Waratahs before asking for a release to return to the NRL were he was a try-scoring machine.

Mark Gasnier: Never entered the Australian system, instead playing in France but his stint in rugby was ugly purely because of the Stade Francais jerseys he sported.

- AAP