My personal experience is that even with the aid of tools such as Roman Key Card blackwood and Jacoby 2NT, natural systems like 2/1 are at a loss when it comes to slam bidding, where systems like Precision triumph big time with their asking bids (alpha, beta, gamma, epsilon etc etc.). It's very crucial for example to know if partner has second round control in a specific suit, in order to reach a slam. Can anyone shed some light? An efficient method of cue bidding perhaps?