The ability of fellow owners to veto a trade is one of the most important checks and balances in place to help protect the fairness of the game.
The ability of fellow owners to veto a trade is one of the most contentious elements of the game, which can lead to heated arguments and name-calling on the league's chat board and trade chat.
First, some background: In order for a trade to be vetoed, 10 owners must click the "veto" button. Clicking "approve" or not clicking a button at all counts as approval. If 10 or more people vote to veto a deal, it does not go through. The players are all returned to their original teams. The names of those people who voted to veto the trade will appear in the trade review screen. If nine or fewer people vote to veto, the trade goes through and there's no way to know how many people (or who) voted against the trade.
Every year, it seems, most leagues follow a similar pattern. Someone makes a deal (often involving a new owner) that other owners feel is unfair. The people involved in the trade protest loudly that "it's my 25 bucks, we should be able to run our teams the way we want!" Other owners accuse the team perceived to be getting the better end of the deal of "raping a noob" or something very similar. The parties to the trade ask people to explain why they vetoed, a couple people will, others say, "it's my veto, I'll do what I want with it!" Someone invariably threatens to quit before cooler heads prevail, the trade goes through (or it doesn't) and everyone moves on. By the middle of the season, it seems like everyone basically knows what they're doing and the vetoes essentially disappear.
Every year, the pattern repeats itself as new owners rush to make deals before they really understand the relative value of players.
Everyone has their own criteria for determining if a trade should be vetoed, so this will not serve as an absolute guide. It will, however, hopefully give new players an idea about what to look out for when making and evaluating trades.
Collusion: This is the #1 most defensible reason to veto a deal. In its most egregious form, this consists of an owner who secretly owns two teams in one league and trades back-and-forth between them. We have not had any instances of that in Ryan World, but it has happened (or been strongly suspected of happening) in other worlds. It can also take subtler forms, which are invariably almost impossible to prove. It generally manifests itself in a trade where an older, overpaid player gets dumped for some good prospects.
Taking Advantage Of A New Player: These are the ones that generally spur the slap-fighting described above, and are seemingly an annual rite in public leagues. A new player, itching to make a deal, ends up giving away great prospects for crap because he doesn't understand that a starting pitcher with a great overall rating and great VR/VL splits is worthless if he has a control rating in the 30s or a durability of 9. Or that a pitcher with great control still won't get major league hitters out if his splits are in the low 40s. Or that they should know what they're doing if they trade for the guy with the worst contract in Ryan World history. Older owners need to police themselves and new owners need to take their time rather than rushing into a deal before they really understand the game.
Straight Cash, Homie: These are a point of huge contention in a lot of worlds because there's really no consensus. Can you trade a good player for a terrible one and a wad of cash? Last year, one of these trades got vetoed here, so the answer is presumably going to be "no" again this season. Owners generally don't have any problem at all approving a trade with cash if that cash is going to be used to cover a big salary for one of the players involved in the deal, but straight-up "selling" a player is generally frowned upon.
So what will prevent all the unnecessary drama? Owners who have questions about a trade should post something on the league chat board before vetoing it. It's important to remember that when prospects are involved, your "advanced scouting" budget can have a big impact on the projected ratings you see. That means that a trade that looks like a huge rip-off to you might look fair to someone who has a higher (and likely more accurate) advanced scouting budget.
If you have a question, ask! It's a lot better to have an open discussion on the world chat and then decide whether to veto or not. You might learn something during the discussion and then people don't get blindsided by 24 hours of silence, followed by a veto.