The first convention I invented (about 13 or 14 years old I guess) was 2-way jump shifts, where a JS is either a normal, natural SJS or a mini-splinter with shortage. I also "invented" 1-level Lebensohl after a takeout double and using a 1NT response to show diamonds (and nothing about spades) after 1

♣ - (1

♠) along with several other (long forgotten) conventions before ever meeting a real life bridge partner.

When I did meet a bridge partner he mentioned this idea about using both 2

♣ and 2

♦ to show strong hands but he could not remember how it worked. I had never heard of Benjamin at this point so I thought about it for 5 minutes and came up with a workable structure that more or less resembles what I now know as Reverse Benji, which we ended up playing the entire duration of our partnership.

The same partner had some other ideas too. He insisted on playing something he called the "2

♣ Asking Range" convention (Opener's rebid of 2

♣ is an artificial relay), which unfortunately made several hand types effectively unbiddable. I did manage to talk him out of that one after a couple of months though.

Some more recent ideas that I have abandoned include:-

Bambi (BAlanced Majors, Big 1NT) - {1

♣ = 10-14unbal; 1

♦ = 15-22unbal or 18-20bal; 1

♥ = 12-14bal or 21+bal; 1

♠ = 15-17bal or 23+bal; 1NT = any unbal GF};

Tropic (I think it was TRansfer OPenings Incorporating Canap? - {1

♣ = 13+bal or 16+unbal or 11-15 4414; 1

♦ = 10-15 4+

♥; 1

♥ = 10-15 4+

♠; 1

♠ = 10-15 4+

♦ no 4M; 1NT = 10-12bal; 3

♣ = 10-15 6+

♣};

Big Heart - {1

♣ = 10+ 4+

♥; 1

♦ = 10+ 5+

♣ or 10+ 5+

♦ or 17-19bal; 1

♥ = 11-13bal or 20+bal or 20+ with

♣,

♦ or

♠}; 1

♠ = 10-19 5+

♠; 1NT = 14-16bal};

FP - {P = 0-7 6+

♣ or 12+ OB in

♦/

♥/

♠ or 15-17bal or 19+ 3-suited or 20+ any; 1

♣ = 12-14bal or 18-19bal or 12+ 5+

♣ or 12-18 4414/4144; 1

♦ = 8-11 any; 1

♥+ = 0-7};

2 Under (SNT) - {1

♣ = 10+unbal 4+

♥ or 18-19bal 4+

♥; 1

♦ = 10+unbal 4+

♠; 1

♥ = 12-14bal or 15+unbal 5+

♣ no 4M or 18-19bal <4

♥ or 20+bal; 1

♠ = 10+unbal 5+

♦ no 4M; 1NT = 15-17bal; 2

♣ = 10-14unbal 5+

♣ no 4M; 2

♦ = W2M or Acol 2

♦}; and

2 Under 2 (WNT) - {1

♣ = 10+unbal 4+

♥ or 18-19bal 4+

♥; 1

♦ = 10+unbal 4+

♠; 1

♥ = 15-17bal or 15-19unbal 5+

♣ or 18-19bal <4

♥ or 20+bal or 20+ 5+

♣ no 4M; 1

♠ = 10-14unbal 5+

♦ no 4M or 15-19unbal 5+

♦ or GF 5+

♦ no 4M; 1NT = 12-14bal; 2

♣ = 10-14unbal 5+

♣ no 4M; 2

♦ = W2M or Acol 2

♦}

I could probably fill a couple of full length bridge books with the ideas I have had and abandoned realising I could never persuade anyone to play it. Maybe I will go back and develop a couple of them properly now I have a little time after taking a furlough/voluntary redundancy package. Probably not though - so few bridge players want to try anything different out ever. It is kind of sad really.