This came up in another thread a week or two ago, too... stepping back from this specific auction, would you gentlemen share your rules of thumb for when you think returning to a major after minor-suit agreement is an offer to play? My own tendency is that if you've passed up only one previous chance to support a suit, delayed support is obvious (e.g. 1♥-2♦-3♦-3♥) but having passed up two previous chances to support a suit - as with spades in this threads auction - my default is to treat the 4M bid as a cuebid in support of the agreed minor. I am aware of the fact that I use cuebidding more (and RKCing a lot less) than is popular these days... but the whole subject of continuing to explore for a 2nd fit after having already found one strikes me as a low priority area of a system. IMO being able to get to 4M instead of 5D should be a very high priority in your system, higher than having those bids assigned for slam bidding. I mean for starters you could easily have a 6-2 fit in either major here (responder could be 6-4/6-5 with opener having 2 hearts, or responder could be like 2551 with opener being 6-4 in the pointed suits), and it is important to find that out rather than play a game that needs 11 tricks. Being able to play your 8 card major fit has to be a top priority imo. Add to that that in an auction like this you could easily belong in a 5-2 fit (as here), and it becomes super important to be able to have 4M as natural. It's not like being unable to cuebid either major is going to stop you from ever bidding slam effectively. The truth is that 4M natural will ALWAYS help you when you need to play in that contract (it's the only way to get there at that point), but 4M cuebid will only necessary to bid slam effectively a fraction of the time, so even though 4M cuebid would be more frequent, it does not mean that it is better to play it that way.