Bonus points are:
1) a good way to separate teams in the league with the same win/loss record in a fair and transparent manner
2) a good way to incentivise and reward attacking cricket (taking wickets, scoring runs)
3) a good way to add interest to the end of one-sided games once the result is effectively decided
Bonus points should not:
1) make up be the majority of points on offer
2) incentivise teams to play negative cricket or give up on trying to win
3) be a factor in whether to bat or bowl first
Can we all agree on that?
I'm sorry but I don't agree. In some games they might do in others (most, in our league) they do not.
If you want to know who is the better team between one who took 7 wickets in a game vs a team who only got 6 wickets in another is not fair or transparent. A team who were easily winning might shove their 9, 10, 11 in to have a net as it doesn't make a different to their points total, but the losing team pick up cheap bonus points. A better way to separate teams would be head to head results and then net run rate.
I'd love to know which teams think taking fewer wickets or scoring fewer runs is an advantage. Yes you can bowl wide outside of off to a packed off-side field but that is still a legitimate way to take wickets when you have scoreboard pressure. You can't bowl down leg or use too much short stuff anyway.
If you really want that them, have a single point for taking all 10 wickets in either innings. 1 point for get 90% of the runs or getting the runs with 4 overs to spare (40 over cricket). 20 points for a win and 10 for a draw/tie/cancellation. Maximum 2 bonus points available per team.
Some people seem convinced that scrapping bonus points will suddenly enable teams to score a huge amount of runs. I'm pretty sure everyone is trying to do that but usually fail. The bonus point system in our league means that a team can block out to deny a comfortably better team 5 points, which is 20% of the total available. That is usually a motivation for some players. They don't actually try to score many runs to gain points. They like to spoil someone's day rather than achieve something positive for themselves.
I think bonus points add an unnecessary layer of complexity in an already complex game. They promote stodgy, back-to-the-wall batting at the end where the emphasis is on denying to opposition points rather than gaining your own. They draw out an already long day (which discourages participation) and they often mean lower order batsmen lose the freedom to play how they want. They are pressured into blocking and scraping a few extra runs instead of having a go at playing some nice cricket. Not everyone of course can or does want to do that but the choice is there.
Using net run rate as a separator in the league standings is enough to encourage a team not to jack it in too early. If you get thrashed, it will significantly harm your NRR. The point of NRR is that it doesn't come into play until two teams are on the same points from the results of their games. A team can just aim to get their bonus points without ever really trying to win a game and end up higher in the league that a team who actually wants to participate in a contest.