Opening 17-19 balanced
The problem of what to open with 17-19 balanced was solved by Ron Klinger in The Power System: Five Bids To Winning Bridge. However the price of his 17-20 1NT opening was the loss of using 1NT to open the far more frequent 15-17, 14-16, or 12-14 balanced hands, and that has proven too high a cost for everybody.
Aside from that and some not-allowed-everywhere ideas, like the strong one heart opening discussed in previous blog posts, this leaves these four opening options: 1C, 1D, 2C, and 2D.
Opening 1D with 17-19 balanced has problems, even though it is used by a number of good partnerships. The sequence 1D-1NT wrong sides the most likely strain, having the weak hand play notrump. In addition the range of the 1D-1NT response is an issue - if it is not forcing, it is either something to be passed, like 3-5, and a waste of a bid, or something that is an invite opposite 17-19, such as 5-7, and not used much, and stronger responding hands pose a problem. If 1D-1NT starts at a higher range, then one has to either pass with a weaker hand, when 1D can be a poor spot, or make some suit bid without much values. Often the structures with 1D containing 17-19 balanced have to resort to responding 1M sometimes with just 3 in M, and that imposes follow-up complexity. It's not a pretty sight.
Opening 2C or 2D with 17 balanced doesn't work, since many of the opponents will be playing 1NT as 15-17, and thus when responder is weak the opponents will often be playing 1NT, instead of the 2NT forced by the two level opening. However 2D as 18-19, or 2C as 18-19, 18-20 or 18-21 are all workable, although my studies show that poor 18s can be too light, such as 4-3-3-3s, and there is a risk undertaken in opening these at the two levels. The 2C opening works better than 2D, since 2C provides room for transfers to either major, allowing for two level signoffs, and finding for 4-4 major fits on the way to 2NT. The cost of using 2C instead of 2D is that stronger game forcing hands have to open something other than 2C (such as 2D), often with bidding room and/or entanglement issues. In the style that I prefer, following the ideas of Kokish, a game force opening is only made with real game forcing playing value, and thus is not that frequent. In that case I don't mind exiling the game forces to a worse bidding location, in order that the 18+ balanced hands are well treated. However if your style is currently to use the 2C opening on many close-to-game-force hands, then you are better off either playing 2D as 18-19 balanced, or using BRASS to put the 18-19s into your 2C opening.
All that is to say, with 17-19 balanced your best opening is 1C. It allows the partnership to get to 1NT when responder is weak. It provides room for transfers where permitted, or other major fit methods as wanted. The downside is you have to have some decent structure here. The current standard approach of 1m (can be 18-19 balanced with the minor)-1M(can be light);-?, and having opener rebid either 2NT (18-19 balanced without 4 in M) and 4M(raise with 18-19) is flawed when light responses are possible, and if light responses are not possible, the partnership can languish in one of a minor when 1NT is the landing spot.
The other flaw in opening 1C with 17-19 is whether or not it is combined with much weak hand types, such as 11-13 balanced or minimum openings with unbalanced club hands. If the minimum for the 1C opening is much like standard, then mild competitive bidding by the opponents can pose problems. Say it goes 1C-2S(overcall)-? Or 1C-2S(overcall)-P-P;-?. On the first sequence responder would like to compete on most 6-9s, if opener is 17-19 balanced, but if opener can be a standard minimum, responder must pass most 6-9s to keep the partnership from getting to 2NT or 3 level on not much values. On the second sequence, if responder is passing 2S with most 6-9s, opener would like to show the extras of 17-19, but if opener bids and responder is quite weak this again risks a 2NT or 3 level contract on insufficient values.
For this reason, the big club approach is a better way of treating 17-19 balanced, since after 1C-2S(overcall)-?, responder knows opener has 16/17+, and can compete with game interest. However as discussed in the last post, using the big club can result in less than optimal treatments of unbalanced hands with no five card major. One thing to consider if playing in ACBL events, is if the 1C opening promises at least 15, then transfers and other artificial methods can be played over the 1C opening.
If you don't want to open 18-19 balanced on the one level, the best option is to play 1NT as a healthy 15 to 18-, and then have a 2C or 2D opening for decent 18s and all 19s and poor 20s balanced. The concern here is that the range for minimum balanced hands becomes about 4 points, about decent 11s to poor 15s, a little too wide. Some experts believe that it is not effective to open 11s and bad 12s balanced - for example while Meckwell will open any 11, their world championship teammates have on their respective convention cards "Avoid opening bad BAL hands 1st/2nd". If one starts opening balanced hands at not too bad 12s, then 1NT as 15 to 18- works well. A lot depends on style here as opposed to there being any absolute rights and wrongs. One reason for the Bread N' Butter series is to look at how opening those flat 11 counts fares - do light & flat openings form a key factor in success?
Next up - when balanced and unbalanced live together.