You are the dealer, and the player to your left told you to pick up the making spades trump.
What Should You Discard?
For obvious reasons, no one should have discarded the Ace or the Trump card. The 9 can be eliminated from consideration, because it doesn’t create a void in diamonds.
So there are really only two choices, the Q and the 10. Many of you would have picked the 10 because it the smallest card that creates a void. Discarding the 10 is not a mistake, but it is a dubious move. The better play would be to discard the Q.
Since the Q is alone, she can’t be used effectively as a squeeze card, therefore making her is a equally as useless as the 10. The only difference between the two cards is that the 10 is in the next suit, and Q is in the green suit. There are 5 hearts unknown in play compared that to 4 clubs unknown in play. It is more likely that a heart will be led than a club. This edge may not seem like much, but it does add up over time. An extra trick leads to extra point, and eventually leads to extra win.
Your first priority is to create a void in the color opposite of trump. If that option is not available to you, then your second priority is create a void in the next suit. Your last priority should be to eliminate the lowest card.