Agreed! Premier leagues and super leagues will definitely be affected if a T20 world cup is held every year.
However ICC will not be auctioning players and players will be earning only the match fees. I guess IPL will survive this since players are auctioned and huge money is involved. Good players who will be looking for money still give preference to playing it. But it will be become a bit barrier of other leagues.
Maybe English 100 ball will get some attention because its format will be different than WT20. The last over of 10 balls to be bowled by 3 bowlers might make it interesting.
It can, in a different way.
Look at the WC as a business proposition (for the sake of saying, say 16 teams, twice a year). It'll generate more revenue than IPL for sure from broadcasting, gate money, media rights, endorsements & other co-branding. Now, you have to distribute the money in a way that players are benefited, but across the globe, not 11 crore to Unadkot.
1. Arrange the tournament in different countries in a 4 years cycle (8 hosting rights, some can be shared by smaller boards like BCB/SLCB) - hosts gets significant amount after netting off the cost, which'll increase the financial capacity of smaller boards significantly. This'll help them to develop the infrastructure as well - no point giving 100 countries some status when most of them don't have fundamental facilities to carry on the game.
2. Share broadcasting/endorsement/media money among ICC members in a revenue sharing model; still BCCI should get highest pie, but whatever others are getting is their bonus - 100% IPL money was going to IND/BCCI, apart from the wage of 64 players - but that blocked 3 months for almost every other board.
Now, coming to your question - draft (basically how players will be given that fat pay cheque).
It's even easier,
1. Make obnoxious match fee - say $100K/game for starting XI, $75K for 12th man, $50K for rest squad. 16 teams, 4 groups > 24 games > 4 QF > 2SF > F; may be a 3rd-4th play-off to increase chances of IND, PAK, ENG, AUS, SAF, BD to stick till last day - that's 32 games; for a 15 men squad each total match fee is
(11 X 2 X $100K + 1 X 2 X $75K + 3 X 2 X $50K) X 32 = $84.80mn
That's exactly around the amount 8 IPL teams are paying. Difference is, instead of paying $1.5mn to Unadkot's passport, now that amount will be equally distributed to 240 players. A players playing 4 games (QF loss), taking home $400K. $100K is just a figure - business volume will determine the final amount, it can be higher, lower.
This is for one WC - make it twice a years .....
2. Make obnoxious amount of price money - say $100mn is the bucket for 16 teams (Boards).
Winners takes $30mn,
Runners-up 15mn
3rd 10mn
4th 7mn
Losing 4 Q Finalist 16mn (4mn each)
Last 8 16mn (2mn each)
6mn for individual awards
This, makes an incremental payment for best players regardless of nationality + reward for the Boards that nurture their talent best.
3. Pay the guarantee money to the 16 participating boards (And few other associates as well) - this is basically the revenue sharing. It's not necessary that it has to be equal share, BCCI can have higher share because they are taking care of more cricketers as well.
BUT, BUT ..... with a condition that every Board will have to show audit report on how much they are paying to the players - this covers from Virat Kohli to Ranji division 2 reserve (In BD context from Shakib to this new kid Yasin) - Boards can decide which way/category they are going to split the money (basically central contract among National, FC players, match fees, & may be retired players' pension), but the total pay out has to be agreed by ICC - gone are the days of free business class trips for Chairmans' and their families, cham***s at will on Board's money, earned by the players, selling entertainment to the tax payers.
4. Teams (Boards) will have the rights of own branding, therefore their earning will increase because of the WC, which is highest sold event in any country compared to respective PLs & SLs, which includes BCCI as well - now, instead of Mumbai, Mukesh Ambani'll pay for Indian Indians as well. IND still might be the highest bidden jersey, because of the market size that logo is targeted, but this time even PNG can get a fortune from Tata Motors - because eventually, 9 out of 10 people bothering for the WC actually a potential market for Tata Motors, though a single Tata car might not be seen at Post Moresby.
5. Still, Virat Kohli is an endorsement icon because he is Virat Kohli for India - I doubt even a thousand people gives a damn for Virat Kohli of RCB; next year he can be Virat Kohli of CSK - which means, top players won't lose their endorsement money (which is for Kohli's case over 80%), rather it should increase much more if he can become Bhuban for India once in 4 years, than 10 times every year for RCB.
For average cricketers across cricket globe, this is dream - his earning'll increase significantly, instead of 64 non Indians. I for one, never bother for what match fee or central contract fee Shakib is getting - to avoid tiresome road journey, he rented a helicopter for few days when he visited his home town .... and that money isn't coming only form BCB or IPL, it's coming from ATv, BTv, CTv, DTv, ..... ZTv, Alpha group, Beta industries ...; it doesn't matter much for Tamim or Mushi either, BUT it's the minimum amount paid to the poor fellow playing semi pro club/FC cricket and keeping his cooker running that does matter. You can check, top Indian players' IPL earning is just the cream on their caviar palate, so was PSL for Afridi.
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Just kidding - it won't happen, but looking at the numbers, potential are unreal. Cricket as a global sports economy, will surely reach among top 10 sports. Only if they could ensure that rest 8 months there'll be enough Test/ODI Series and FC cricket is well taken care of; otherwise money won't save cricket from extinction.