
https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
Here I have one small trump, no aces and nowhere to go in the 2nd round. This is the kind've spot where my team has a good chance to lose 2 points no matter what path I take, whether I pass and hope for the best in the first rd, donate, or pass and then get a chance to call in the 2nd round and donate in Next or pass in the 1st Rd and pass in the 2nd round with a hand that blocks nothing+no off aces.
The poor defensive and offensive nature of my hand means my team has a good chance of losing 2 points no matter what I do, therefore I might as well take the line that eliminates 4 point enemy loners. BTW this is the kind of thought process that goes into donating at non 9-7/9-6 scores. It's not about whether you're guarded or not. You don't simply donate becuz you're unguarded. And it's not so much about the upcard--although the Jack upcard is a special situation in it's own right. And the score only plays a minor role. Why does the score not matter that much? Becuz when you have one of those crap hands where all paths have a good chance of leading to your team losing 2 points, being say down 5-1 or 6-3, or 0-4, etc doesn't magically make that problem go away. It's still there and you have to deal with it whether you like it or not. This is why it's the cards you hold that play the predominant role in one's donate decision making outside of 9-7/9-6 scenarios.
Ok let's get to the results of the hand. My donate got lucky and scored a point becuz my P was loaded. If I would've passed, my P would've either called or went alone and my team still would've only gained 1 point. So the net cost of this donate was: 0.

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
1 trump + an off ace is a donate for me vs a Jack whether I have a 2nd round hand or not. Special attention needs to be paid against Jack upcards. I may not donate with this holding vs another upcard, but vs a Jack it's a must. Notice the score is 0-0. I know some good players who dogmatically do not donate at 0-0. It's early in the game...etc. I don't understand this type of thinking. "It's early in the game" would seem like perfect logic to donate as your team has ample time to catch up. The easiest donates should be the early game donates and the late game donates. It's the mid-game donates that hurt the most. Donating when one is up 7-6 or tied 5-5, or 6-6. Those are the donates that sting and yet they still have to be done in the right situation. Besides all that the saying "It's early in the game" is a dangerous way of thinking. IMO one should play to win, doing what's best for his team, EVERY SINGLE HAND. One does not simply get to take some hands off becuz "It's early in the game".
Results: This donate captures the rare +3 pt swing for my team. I called and my team miraculously scratched out a point (+1). If I had passed, everyone would've passed and I would've been forced to donate in Next and get euchred (-2). That's a 3 pt swing for the good guys. Notice if I pass in the 2nd round S2 has a lock 4 point loner. One could almost argue that my 1st rd donate was a +5 pt swing, but I would never pass in the 2nd round in that spot. I would never do that to my team. Always remember euchre is a team game. If you're not willing to take a good euchre for your team then you're not playing for your team, you're playing for yourself--to protect your precious euchre stats, your image, or something else--whatever the case you're not playing to win.

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
No trump + 1 off ace vs a Jack upcard is an auto-donate. This is a very scary situation.
Results: My donate got euchred, but had I passed S2 would've called and his team would've netted a 2 pt march assuming they both played the hand well (I would've led the AD). So the effective cost of my donate was: 0

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
It's 0-0 and I have one of those hands again where my team is in trouble no matter what path I take. I have one low trump, no off aces, and no defense/no where to go in the 2nd round. In these unfavorable spots, where the probability of losing 2 pts is higher than normal no matter what line S1 takes you might as well take the path that blocks a possible 4 pt enemy loner.
Results: My donate got euchred (-2). Had I passed, S2 would've called and gotten 1 pt. Cost of my donate: -1.

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
No trump, 1 off ace vs a Jack = auto-donate.
Results: My donate gets euchred (-2). If I had passed the dealer would've made a 4 pt loner. My donate creates a +2 swing for my team.

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
Two low trump, no off aces, no 2nd round hand vs a Jack = donate. I don't donate with 2 low trump very often, but vs a jack I'm not messing around. If I had 2 low trump + an off ace or I had Ax in trump so now only JJX can get by me, that would be enough for me to gamble and not donate. (except at 9-6/9-7 scores where I'm always donating if unguarded)
Results: My donate gets euchred (-2). If I had passed, the dealer would've called and gotten 1 pt (I would've led the 9S). Cost of my donate: -1
Although this is a little debatable as there is a pathway for the enemy to get two points. If you play out the hand, S2 will end up in a spot on 4th street where he'll have to guess which King to lead, and if he leads the "right" one, the KD, and S4 understands he needs to play off and gamble on that fresh KD because all the trump are gone, then the enemy team will net 2 pts. To be conservative tho we will ignore this scenario.

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
This is one of those spots where the score plays a tie-breaker role for me. Having a good 2nd round hand makes me not want to donate vs a TD, but having no trump + only 1 off ace makes me want to donate. At 0-0 or 4-4 I'd probably pass, but up 2 or more I'd rather donate anytime I have no trump with 0 or 1 off aces. Once I donate the worst case scenario for my team is 2-2 with the deal which equates to 51% equity. I'd rather protect that equity in this spot.
Results. My donate got euchred (-2). Had I passed, S2 would've named it and their team gets a 2 point march assuming they play the hand well and I lead off with a spade which is what I would've done. Cost of my donate: 0.
Tangent: I'd rather lead off a spade here than a tripleton Ace. Although lately I've been seriously questioning that logic. Maybe it's best to lead the ace, tripleton or not. It still brings out enemy trump on the first lead which is good or walks which is even better and this lead could create a chance for my P to overtrump the maker, and it could allow my P to short suit himself. I guess the advantage of not leading off with the tripleton ace is by holding it back it has a greater chance of going on the later streets after trump has been played but I'm not sure at all that this supposed advantage outweighs the plus side of simply leading it.

https://worldofcardgames.com/#!replayer ... %3A1%7D%5D
I hate donating up 7-6, but no trump no aces vs a Jack makes this automatic. In fact even down 7-0 I would donate vs a Jack with no trump+no aces. That's how bad this spot is to me. It's literally the worst possible spot in the game.
Results: My donate got euchred (-2). Had I passed, the dealer would've made a 4 point loner. My donate creates a +2 swing for my team.
Ok so that's the 8 donates. Let's add up the results:
0+3+0-1+2-1+0+2 = +5 pts.
So that's 8 donates that ended up netting +5 points for my team. Translation I ran hot on my donates yesterday.