kugw, on 2016-January-20, 18:01, said:
The most common treatment for 4441 hands is to open the suit below a red suit singleton or the middle suit with a black singleton. Another modern alternative is to open 1
♦ on any 4441 except a singleton diamond, in which case 1
♣. Both of these methods provide slightly better clarity on major suit length than the older approach with the key auction being 1
♥ - 1
♠; 2
♣. The common treatment has almost no downside; the alternative makes the auction 1
♦ - 2
♣; 2
♦ more difficult, which in turn has some knock-on effects (with similarities to a 5 card major system) but gains the upside that any new suit rebid after a 1M opening promises 5+ cards in the major.
On the specific hand, many others have already provided Acol auctions (all starting with 1
♦ you will note) so it seems unnecessary to repeat the effort again. A lot depends on the handling of a singleton in partner's suit. While there is generally very strong agreement that opening 1
♥ with this shape is a poor idea, there is much less agreement about the best choice of rebid.