This is a complete detailed bridge bidding system using 1C as a strong and forcing bid with most hands 16+ pts unbalanced or 17+ pts balanced. The system employs transfer responses over 1C. Included is a ACBL convention card. For complete system see my blog.
Looking for someone to learn this Precision system to play on bridgebase.com
There is an obvious defense to Bergen, which allows opponents to enter the bidding, when they normally wouldn't have the values to.
3C (if 7-9 or 6-9): Double = takeout double of the major. Don't so much need hcp as distribution as they are unlikely to be able to play in 3CX. Might find any easy sacrifice or get to play it, especially if opener cant bid game.
3D (If limit): Double is for lead
If people are playing Reverse Bergen you do the other way round. 3C-X: lead, 3D-X: takeout
1M-3M : use this as a mixed raise (Bergen style) 7-9 4 card support
1M-2N: standard forcing raise plus 4-card limit raises. You have to change your responses to what your would do over 1M-X-2N (Dormer). Of course, you could use more complicated methods, there are many methods for 2N as a limit+ raise available on the internet or in books.
Pre-emptive raises: just pass, raise to 2M or 4M depending on your playing strength.
Using this method you don't give away easy doubles of artificial bids
Thanks to John Montgomery's Revision Precision for showing the error of my ways.