You are playing the 2/1 game force system and you have the following hand when partner opens 1
.
QJ7 
7654 
K98 
AQ10 what do you bid?
You have a balanced hand with 12 HCP, bid 1NT forcing. Replace the 10 with the J, to give you 13HCP. Now what? Still bid 1NT, do not bid 2 (you need five), and your hand is balanced. And do not bid 2NT (you need four spades).
With a balanced hand and 12-13 HCP bid 1NT over the major suit bid. If partner rebids spades or shows a 4-card suit, next bid 4 – game values with no interest in slam. If you play [ilink url=”http://csbnews.org/new/conventions-combined-bergen-raises/?lang=en”]Combined Bergen raises[/ilink] you would bid 3 with the above hand showing a limit raise with three card supports in spades.
You have the following hand K93 K432 2 AQ1098 what do you now bid?
You have 13 points, bid 2 to show 13+ points and an unbalanced hand. However, if you replace the Q with the J, you would not bid 2 but 1NT forcing and then bid 3 to show a limit raise with three card support. Playing [ilink url=”http://csbnews.org/new/conventions-combined-bergen-raises/?lang=en”]Combined Bergen raises[/ilink] , you would bid 3, limit raise with three card supports for the bid major.