THE relatively tiny Irish sporting scene was once divided along strict lines of segregation, but it's now a 'College of Knowledge' that crosses all boundaries.
No longer are sports performers 'just' a boxer or a golfer or a Gaelic footballer, soccer player, athlete or rugby player.
An increasing number of top-level sports people have expertise to share in other spheres of activity, and they are finding minds and doors opening that were previously firmly shut against 'outside' influences.
Qualifications help, of course, as is the case with Donegal boss Jim McGuinness, who recently joined Celtic as a performance coach with their academy.
McGuinness spent years honing his expertise in sports science and psychology, but it was his spectacular influence on underachievers Donegal as much as his academic ability that persuaded Celtic to invest in his services.
Former world super-bantamweight champion Bernard Dunne worked alongside Jim Gavin with the Dublin U-21s and caused a stir when he was unveiled on New Year's Day as a performance and lifestyle coach for the senior team.
Dunne commands respect for his achievements in the ring and when he speaks the Dublin footballers will listen because the ex-boxer has performed to the highest level in one of the toughest, most dangerous sports in the world.
McGuinness and Dunne are the latest in a growing number of sporting exponents here whose ability and ideas can be transposed to great effect in other sports.
There are many others who have been crossing the great divide, and no doubt more will follow.
Qualified sports psychologists are growing in number and influence in all sports, but 'performance' and 'proven achievement' is the X factor for ambitious managers and players seeking success in all codes.
Everybody wants the edge on the opposition and if that means going outside the accepted norms of their own sport, then so be it.
The growth of sports science and exercise courses is a factor in providing new expertise, but winners command respect and that's a huge advantage in getting players and performers to actually listen to the messenger.
Well, he did, and that's why Padraig Harrington employed Alred to give his practice and playing routines a makeover.
The potential rewards, for a Luke Donald or a Padraig Harrington, from finding a little extra in their game through the use of outside contributors, are immense.
In the world of soccer, what a bonus for Celtic if McGuinness has a decisive role in producing even one who becomes a first-team player and then a multi-million transfer target for the game's rich elite? If he does that, then Celtic's investment in the Donegal boss will have paid off handsomely.
Can Bernard Dunne influence a Dublin player or two to reach deeper within themselves than they otherwise might have done when the chips are down in an All- Ireland final?
If that happens, Dunne's input would be incalculable for Gavin.
All those incremental, often intangible influences of men such as McGuinness and Dunne are aimed at producing winners, medals, and, in professional sport, material reward.
The point is that Irish sportspeople are hungry for anyone or anything that can make them better than last year, and the list of crossovers from one sport to another is growing at a fascinating rate.
Top 10 crossover achievers from other sports
1: Jim McGuinness
Donegal GAA to Celtic FC as a performance consultant
McGuinness was a member of the Donegal 1992 All-Ireland-winning squad, but his contribution in reviving an ailing county from the depths of defeat in 2010 to All-Ireland champions in 2012 is his biggest achievement to date.
We eagerly await the new campaign to see if McGuinness can keep his side winning matches in 2013.
2: Bernard Dunne
World champion boxer to Dublin GAA as a lifestyle coach
Former European and world super-bantamweight champion Dunne is an eloquent and engaging speaker as he has proved in his boxing analysis role with RTE. He can have a very positive influence on the Dublin footballers.
3: Mike McGurn
Rugby league to rugby union to GAA
Originally a Gaelic footballer and athlete, McGurn made his name professionally in rugby league before emerging as a top-level trainer with the Ireland rugby union team. He also made a big impact with the Armagh footballers and with Bernard Dunne.
4: Bryan Cullen
GAA to Leinster Rugby
Dublin's 2011 All-Ireland winning captain. Qualified with a PhD in exercise physiology from DCU and works with the Leinster rugby development set-up.
5: Philly McMahon
Dublin GAA to Shamrock Rovers
McMahon is another DCU graduate and top-grade GAA performer with Dublin. He is now training and fitness coach with Shamrock Rovers.
6: Enda McNulty
GAA to sports and business
McNulty won an All-Ireland with Armagh in 2002. Now runs Motiv8, a company dedicated to performance improvement in GAA, rugby, other sports and in business.
7: Michael Carruth
Boxing to GAA
Olympic Gold medal-winning boxer in Barcelona 1992, Carruth is masseur with the Dublin hurlers and formerly operated in that role with Westmeath footballers. Carruth also has the vital experience of achievement that is an inspiration to players and teams.
8: David Matthews
Athletics to GAA
Former Olympic athlete David Matthews brought his athletics know-how to his fitness training of the Cork hurling team under Jimmy Barry-Murphy's management.
9: Mark Rohan
Paralympics to GAA
Mark Rohan was among the top Irish performers of 2012, winning two gold medals in the Olympics. His motivation skills and sporting knowledge are being utilised by the Westmeath footballers.
10: Sean Cahill
Athletics to GAA
Another ex-Olympian, and with his wife Terri, coach to top athlete Derval O'Rourke and others, Cahill answered the call of Seamus McEneaney to be a fitness coach with the Meath GAA team.