Best union-to-league converts Ray French Rugby League legend

Jim Sullivan, Gus Risman and Tom van Vollenhoven should technically all be on this list but they are not.

That is because they achieved such great things in rugby league that they have made it onto my list of greatest rugby league players.

Here are six more former union players I feel have made a massive impact in the other code.

Trevor Foster

With over 65 years' service to the game of rugby league, and Bradford in particular, no-one, on and off the field, has shown the same passion for the 13-a-side code as this former Newport back-rower.

Martin Offiah: Thrilled crowds with his try-scoring feats

A 1946 British Lions tourist Down Under, a regular pack man for Wales and the inspiration behind the reforming of the Bradford club when it collapsed in the early 1960s, Trevor is still Mr Rugby League in West Yorkshire.

Martin Offiah

Signed as an unknown from Rosslyn Park rugby union club by Widnes coach Doug Lawton, "Chariots proved the main attraction in the late 1980s and 90s with his sensational try-scoring feats down the wing.

Over 500 tries in both Britain and Australia are indicative of his ability to break down the best defences.

Lewis Jones

Known as the Golden Boy when he made his Wales rugby union debut as an 18-year-old against England in 1950, his move north in 1952 for a record £6,000 sum rocked the rugby world.

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He proved his worth with both Leeds, for whom he scored a record 496 points in a season, and for Great Britain, for whom he scored a record 278 points on a Lions tour within five years of switching codes.

Billy Boston

Having signed in secret while representing the Royal Signals army rugby union team in 1953, Cardiff-born Billy Boston proved an immediate sensation, representing the British Lions on tour Down Under after playing in just five games for Wigan.

He proved his worth by scoring 36 tries in 18 matches and went on to score 571 tries in a career spanning 17 years.

Lewis Jones: His move to Leeds shocked the rugby world

Jonathan Davies

The supreme entertainer whether scoring tries by virtue of his uncanny instinct and pace off the mark or by scoring goals with unerring accuracy, Jonathan Davies was a point-scoring machine with both Warrington and Widnes.

His personality and character on and off the pitch endeared him to rugby fans, while his current activities as a commentator and pundit on the 13-a-side code continues to enhance the profile of the game.

David Watkins

League and union legend David Watkins repaid his £16,000 fee from Salford many times over with his feats at The Willows. His impact as a side-stepping midfield back was instant, while his appetite for points-scoring has rarely been matched.

The former Newport rugby union star's world goal-kicking record of 221 goals in 1972/73 is likely to stand for all time, while his run of playing and scoring in 92 consecutive matches for Salford epitomises his appetite for rugby league.