Mr. Robert B. Ewen published his book Doubles For Takeout, Penalties, and Profit in Contract Bridge in 1973 and perhaps unwittingly contributed to the principle of the Equal Level Conversion.

The problem for South is that South has the values for a Takeout Double but not the distribution. South would prefer to show both suits with a Michaels cuebid but lacks an additional Spade to conform to the 5-5 distribution as required. As Mr. Robert Ewen describes in the book: “After a 1 opening bid by your RHO, you would like to try for a Spade contract by making a Takeout Double, but you would also like to advertise your powerful Diamond suit by overcalling. Since you are fortunate enough to hold your length in the two higher-ranking unbid suits, you can do both. First, make a Takeout Double; if partner responds in Spades or (improbably) in Diamonds, all will be well. If he misguidedly mentions Clubs, however, simply direct his attention to the other two unbid suits by converting to Diamonds.”

This was rather the beginning of Equal Level Conversion. The designation of the concept is such that the player has not increased the level of the auction by bidding, ergo: Equal Level.

Another example of an Equal Level Conversion follows

The question among bridge players is: which bid is most appropriate for South in the balancing seat. There are many arguments for bidding 2, but there are as many arguments for employing the Equal Level Conversion with a double and then correcting if the partner responds in Clubs.

The problem arises when one opponent has opened the bidding in a Major suit and the next player has sufficient values for an overcall, but has a longer Minor suit and a shorter Major suit. According to Mr. Robert Ewen, the Equal Level Conversion double solves this dilemma.

There are mixed opinions about this method and the opinion of Mr. Frank Stewart regarding the book Competitive Bidding with Two Suited Hands by Mr. Max Hardy is presented below:

Competitive Bidding with Two Suited Hands by Max Hardy

With this book, Max abandons his usual role as a reporter and consolidator of modern expert practice in favor of taking a critical look at the modern approach to describing two-suited hands when the opponents have opened the bidding.

His major target is the Michaels Cue Bid and he shows it no mercy, not only demonstrating its inferiority but also proposing an alternative approach based on the Top and Bottom Cue Bid which is markedly superior both in theory and in practice. In his methods, the cue bid shows the highest and lowest ranking unbid suits (always a Major and a Minor) with the Minor suit being either better or longer (or both) than the Major (which is usually only a 4-card suit).

With a good 5+card Major, he is content to overcall in the Major and hope to show the Minor on the next round. He uses the jump overcall in an unbid Minor to show the same sort of hand with the two lowest-ranking unbid suits. Again, the lowest-ranking suit is longer or stronger; the Unusual Notrump is reserved for two 5+card suits.

With the two highest-ranking suits( Michaels country), he relies on a Takeout Double, and uses the principle of Equal Level Conversion to deny the lowest-ranking suit if partner is inconsiderate enough to respond in that suit.

Although a marked improvement over popular expert practice, this approach has two theoretical flaws:

1. Things can get out of hand if partner jumps in the lowest-ranking suit in response to the Takeout Double (and if he is forbidden to jump, the doubler must raise any time he holds support for that suit).

2. No method is available to permit playing in the opener’s suit when the opening bid has been in a 3-card club suit. The first problem can be solved by using conditional transfer responses to the Takeout Double, while the second problem requires switching to a different system based on conditional transfer overcalls after a 1 Club opening.

Both of these methods were described in the reviewer’s 1981 book, 3-D and the MAFIA Club.

Mr. Eric Rodwell expressed an opinion in an interview with BridgeMatters, which is included below as an excerpt:

BridgeMatters: Do you like Equal Level Conversion Doubles?
Eric Rodwell: I only like converting Clubs to Diamonds. I definitely think that anytime I double and then bid a Major it should be a good hand though I know some people do not agree with that.

BridgeMatters Note: Equal Level Conversion Doubles say if you double and, over partner’s suit response, you then bid a suit at the same level (i.e. equal level), you are not showing extra values. For example, with 13 points and 4-2-6-1, you could double a 1 opening, and if partner bids 2 you could bid 2 without showing extra values.

BridgeMatters: What about the Raptor Notrump, sometimes called the Polish Notrump Overcall, to show four cards in an unbid Major and five or longer in an unbid Minor?

Eric Rodwell: I just find the strong notrump overcall too valuable to give up . . . for any other purpose. Certainly, there are some hands – say they open 1 in front of me and I have AQxx xx xx KJxxx – where it would be nice to play a 1NT overcall showing four Spades and a longer Minor. But I can pass and hope to later make a Club-Spade showing Takeout Double. Or, if I feel like overcalling my four-card suit or my five-card suit, I could do that and get along most of the time. So I definitely have to say I do not care for that idea.

On the other hand, a variation on the theme of the Equal Level Conversion Double has emerged via the team of Mr. Eric Rodwell and Mr. Jeff Meckstroth, which carries the designation Minimum Equal Level Conversion Double. The following examples illustrate this strategy:

The question is whether the partner should overcall on a 4-card Spade suit, overcall on a 5-card Diamond suit, or double and possibly correct if the partner bids Clubs. The Minimum Equal Level Conversion Double of Mr. Eric Rodwell and Mr. Jeff Meckstroth states that the partnership have the understanding that a double is required and if the responder bids 2 (or 3 if the partner of the opener decides to enter the auction), then a correction to Diamonds by South does not indicate additional values since the partnership has stayed at the same level. In order to show additional values, the doubler would jump in Diamonds.

The following example shows a continuation of this partnership understanding:

If the Minor suit is Clubs, then the agreement is to simply bid Clubs. The Minimum Equal Level Conversion Double does not apply in this auction.

The understanding also applies in the following instance

Holding a distribution of 5 Hearts and 4 Spades, the standard preference was to bid 1 Heart. With the Equal Level Conversion Double, the partnership can first double. If the first response is Clubs, then the ECL-Doubler can rebid Hearts, showing minimum and a 5-card Heart suit and a 4-card Spade suit. If the first response is Hearts or Spades, then a possible game may be explored.

The Equal Level Conversion has been a part of national and international tournaments and belong in the reportoire of many expert bridge players as can be seen on the Convention Card of Cohen-Berkowitz and Daniela von Arnim-Sabine Auken and Greta Chai – Foo Yoke Lan.

It is apparent that the Equal Level Conversion Double should apply in only one definite and particular bidding sequence and that its employment in other situations may / should be guided by other, alternative conventional methods. It seems, however, that the last chapter on this principle has not yet been written.