In many situations the quick answer is yes. To do so, however, requires both partners working together as a team.
Some loners, such as a lay-down lone [e.g., five top trump], just can't be stopped. But these hands are rare: the odds of getting a perfect hand are only about 1 in 1500. Even then, you still need the opportunity to call it.
Some players will say it doesn't make any difference what card you lead, but that is just not true. So what is the best defense against a lone call? Given the right opportunities and using the correct techniques, many lones can be stopped on the first lead. For others you may have to wait until later in the hand. In either case, knowing what to play and how to work together with your partner will go a long way toward stopping a lone call. Let's see how it's done.
Before we investigate the ways to stop a lone, here is one tip: if you hold the hold the right, do not lead it. Sure, it will stop their lone, but it may also may pull any trump your partner holds. This could possibly mess up any chance your team has of euchring them. It's a sweet day in euchre land when you euchre your opponents on a lone call!
1) Holding the right.
2) Protected left (left and another trump). Do not use your trump unless you have last play and can take a sure trick!
3) Protected ace (three trump with the ace). Again, don't trump in unless you have last play.
Knowing what cards to play (and a little luck) will stop many lone attempts. While we have no control over luck, there are many tricks that we can use to put the odds in our favor.
Leading the proper card at the start can make the difference between your opponents making one or four points. Here are some common 'correct leads'.
If you hold a single ace, do not lead it. If that ace is the stopper, it will still be the stopper at the end of the hand. Instead, give your partner a chance to play by leading another suit. He may hold the ace to the suit that you lead, which will allow him to make that ace good. The idea here is that if your partner holds two aces, he will not have to choose between them on the fourth trick. How many times have you seen someone get down to the last two cards and throw away the wrong ace? This will stop that from happening.
If you hold two aces, lead the ace in the suit you have the least of. This avoids putting yourself in the situation above (having to choose which ace to discard on trick four), and also tells your partner that you hold another ace. If they happen to have that third ace they may be able to make it good at the end. Even if they don't have the other ace it should still be easy for them to decide what suit to hold to the end. Remember, this is a partnership game, and you must work as a team. There may be times when, as the dealer, 1st seat calls alone and you hold two aces. If it comes down to the end, saving the green ace seems to work best (if there are no other indicators of which suit to hold).
When the lone bidder has the first lead, and you're down to the fourth trick, if your partner throws off an ace he must be holding two aces (assuming he threw off junk on a prior lead). The exception would be if he had to follow trump on every lead. If you hold another ace, it may be the stopper, so save it. If you don't hold an ace, try to hold the highest card in the same suit as the ace your partner threw away. But of course you wouldn't want to save a suit that the maker had trumped earlier in the hand.
Say the lone maker trumps your first lead and leads back trump. If you can't follow suit, this is your first opportunity to show your partner what suit you have stopped. If you have an ace - king combination, play the ace. This tells your partner you hold the king and therefore have that suit covered. Otherwise, you want to play a card in the suit that you can't stop. Let's say you hold a singleton 9 of clubs and hearts is trump. By playing your 9, it shows your partner that you can't cover clubs. Hold a less powerful doubleton in any suit then save it until the last tricks. On the fourth lead you will play one of these, again letting your partner know you have that suit covered. Stopping a lone is all about giving your partner as much information as possible.
If the lone is called from the third seat, as the dealer you should try to discard next, assuming it is a singleton. The idea here is to create a void in next. Concurrently your partner should lead next if possible. In this case only, a single ace lead in next is the correct play. This way you will have the chance to trump next. If the bidder overtrump's, he will need to use a higher trump. This may put you, or your partner in a position to stop the lone.
If your partner has first lead and you have the next play, if you cannot follow suit, trump in with your highest trump. Do this even if they lead an ace. The idea behind this is to draw out bidder's high trump. Your partner may hold the next high trump and now they will be able to stop the lone. A couple of exceptions would be when your partner leads an ace and your only trump is a nine (maybe a ten). If bidder is void in that suit he will just over trump it. Also, do not trump if you only hold a protected left. A protected left is the left plus any small card of the same suit (left-x).
What if you have a hand which seems hopeless to stop a lone? This happens, but to give team the best chance, throw off any single-carded suits first. By doing this, you are telling your partner you can't cover that suit. Your partner can use this information to help decide what cards they should hold. If you have a set of three in a suit, as unlikely as it may seem this suit is you best chance. Of course don't hold them if they are the three bottom cards! If you are 4-suited, hold the double suit till the end.
Remember: A lone call represents 40% of the total number of points needed to win. Teams must draw on their repertoire of skills to prevent these calls from being successful. Over the next pages, I will show a number of lone call and the strategies used against them.