Here is a bid that is often overlooked. This is primarily a first round call from the dealer's position. It is used when the bidding is passed back around and the pick-up will give you (as the dealer) two trump. If you also hold an off-suit green ace, then it may be worth picking up that trump. Two trump along with a green ace is a biddable hand. One of the reasons it works is that there is a fair chance that the cards are more or less evenly distributed. Like many other risky calls, this hand works best against stronger opponents. The main requirement is that the off-suit ace is in a green suit. Keep in mind that you will need your partner's assistance so be sure to give him the opportunity.
The dealer sits in the south position and turns up the 10 of hearts. The bidding is passed around and the dealer picks it up, discarding the jack of clubs.
East leads with the king of spades, North follows suit, as does West. The maker(S) takes the trick with the ace. Perfect, the calling team has their first trick.
Next, the maker(S) leads the 9 of diamonds; he's thinking that if the ace falls, his king will be boss. His partner(N) has the ace and takes the trick. Again perfect, they have now two tricks, just one more needed. No trump played yet.
Because his partner(S) did not play a trump on his first lead but instead led a small off-suit card, this gives North information. This could mean that his partner/maker called on a very weak hand. He now knows not to lead back a trump. Instead, he leads the ten of clubs. West follows suit with the king and maker(S) (with fingers crossed) trumps in. YES, that is trick three and the point needed for the win.
Did you note the score in this game? It is 9 to 7, in favor of the dealer's team. The dealer had the lone stopped in black so no worries there, but a second round diamond lone call by the opponents could have put them out. Even if the dealer were euchred, his team would have another chance to make the needed point next hand. This was just one more reason try a bid on this hand.