We're fast-approaching the start of the 2020 Six Nations on February 1st, which means it's time to once again cue discussion surrounding player selection and, more specifically, foreign-based player selection. 

The global nature of the game of rugby has lent itself over the years to a fluid exchange of players into and out of different countries. Flip on any professional game in England, France, Wales, or Ireland, and you're sure to see at least a handful of players from New Zealand, Australia, and South Africa playing. 

You may also see the odd Welshmen or Scotsmen playing for an English or a French side. 

So why is this a big deal?

Well, most of the tier-1 rugby unions have stipulations in place which restrict the eligibility of players plying their trade overseas. 

We'll use Welshman Rhys Webb as an example. The former British & Irish Lions halfback left his home nation of Wales in 2018 to take up a lucrative contract at French side Toulon. His decision meant that he was no longer available for international selection, and as a result Webb had to miss out on the 2019 Rugby World Cup. 

Different countries have varying details and caveats to their own eligibility rules, but in general a player who leaves a tier-1 country to play somewhere else is unable to play for his country again until he returns home. 

The rationale behind it is to prevent all of the world's best players from leaving home to play in England, France, Japan, or any of the leagues that pay the players top dollar. 

They want to preserve strong unions at home, with the idea that keeping the best players homebound lifts the standard all the way down from the professional level through to the grassroots.

Here's a look at some of the foreign-player policies across the tier-1 nations. 

New Zealand

In New Zealand, the rule is pretty cut and dry. You must be currently playing club or professional rugby in New Zealand to be up for All Blacks selection. 

The NZRU (New Zealand Rugby Union) employs what are known as centrally-based contracts to its professional players. 

How does that work?

The NZRU owns all 14 of the provincial teams in the Mitre 10 Cup, which is the highest domestic-only competition in the country. The NZRU pays the provinces, and then the provinces are responsible for paying their own players. The players are primarily contracted to the NZRU but secondarily contracted to their provinces. 

At the Super Rugby level, which includes 5 teams comprised of players from the 14 provinces, the NZRU owns at least 50% of each franchise. Therefore, players in Super Rugby are primarily contracted to the NZRU, secondarily contracted with their Super Rugby franchise, and thirdly contracted with their province. 

The benefit for the NZRU is that it can manage its players' workloads, as well as get access to any of the players at any time. 

England

Like New Zealand, England's policy is also pretty simple. Players playing outside of England are not eligible for selection, unless there are "exceptional circumstances" due to injury crisis. 

Therefore, if a number of English internationals go down with injury and there are no replacements in the country with at least one international cap, then they can pull a player from abroad. 

The ruling in England poses less of a dilemma than it does in New Zealand because of the amount of money across the Premiership. Players have less incentive to leave for "greener" pastures, because they can score huge contracts at home AND be eligible for international selection. 

Additionally, English players are not contracted to the RFU (England's Rugby Football Union), but are separately contracted to their independently-owned Premiership clubs. 

Over the years, however, there have been a few players to leave and play overseas. Danny Cipriani and Piers Francis both played Super Rugby in Australia and New Zealand, respectively, while Nick Abendanon, Steffon and Delon Armitage, and Chris Ashton are among those who have played in the French Top14. 

Ireland

The IRFU has a hard, but not black-and-white stance on player eligibility. The policy states that players must play for one of the four Irish provinces, and while it's not a steadfast rule, it is closely followed by the union. 

Ireland is another country that uses centrally-based contracts, however in its case only 21 players receive contracts directly from the union. These are meant for players who are regulars in the Irish national team, and can range from $300k - $700k per year. 

Ireland manages to do a very good job of retaining its players, with only a handful of notable players, including Simon Zebo, Gareth Steenson, and Ian Madigan playing abroad. The IRFU's hiring of Australian former rugby player David Nucifora as a player manager in 2014 has been a major factor. 

Their flexibility with the clubs means that they can manage their centrally contracted players' game loads, which is a benefit to those players and their welfare. 

Wales

The rules in Wales are a tad bit confusing, and have come to the forefront of discussion this month, following new coach Wayne Pivac's inclusion of 10 English-based players in the Six Nations squad. 

At the moment, any player playing professionally outside of the country is ruled ineligible for selection, UNLESS they have played at least 60 times for Wales. 

Additionally, a player who signs an overseas contract BEFORE obtaining his first cap is eligible for selection, but must return to Wales as soon as his contract is up. Therefore, a number of English-based players who are uncapped have been picked into the side, including Louis Rees-Zammit, Nick Thompkins, and WillGriff John, and Will Rowlands. 

One loophole that a few English clubs have exploited to be able to retain their Welsh players is offering them contract "extensions" to existing deals rather than letting the current deal end. This was most recently done by Gloucester, who penned teenage sensation Rees-Zammit to an extension in January. 

Like Ireland, the Welsh Rugby Union has a centrally-based contracting system for a number of its most elite players. 

South Africa

In February of 2019, South Africa's union and new coach Rassie Erasmus scrapped the old rule that stated a South African playing overseas must have at least 30 caps to eligible for test selection. 

The powers-that-be realized it was unreasonable to enforce players to play their club rugby in South Africa because of how weak the economy there is. They didn't want to limit their players' own ambitions outside of the game, and removed their old ruling. 

The benefit was huge, with World Cup winners such as Faf de Klerk, Duane Vermeulen, Cheslin Kolbe, Franco Mostert, Francois Louw, Cobus Reinach, Schalk Brits, and Vincent Koch all being selected for the World Cup from overseas clubs. 

The union is aiming to move more and more players towards additional central-based contracts in order to provide them with a bit more income and more flexibility around game management. 

Australia

Australia has the same rule as Wales, governing that a player abroad must have at least 60 caps to his name to be up for selection. Known as "Giteau's Rule", this policy replaced the previous rule in 2015 that required a player must play in Australia, regardless how many caps he had. This was changed to allow Matt Giteau and Drew Mitchell to be eligible for the 2015 World Cup, in which the Wallabies went on to make the final. 

The Australian officials want to see the Super Rugby franchises thrive, and have put the rule in place to prevent a mass exodus of players overseas. 

France

France has the same rule as England and New Zealand, but have little to worry about with regards to native French players. With the French Top14 the most lucrative of competitions, players rarely, if ever, leave to play in another country. 

The dilemma for the French in recent years has been the huge presence of foreign players who live in the country long enough to become eligible for France. A number of overseas players find themselves settling in France permanently and suiting up for Les Bleus. 

Scotland

Scotland in fact have no rules surrounding selection. Anyone who is Scottish or is legally eligible to represent Scotland is an option, regardless of where they play.