Pardon my ignorance, but I have never bet on an event. While watching a ball game on TV, one of the main advertisers is an online betting site (Bet 365 I think its called) and their big schtick is that you can bet even while the game is on. They will illustrate this with something like Toronto +150 or Boston -170. I assume these numbers refer to margins you give or take, but there is no explanation of what they actually mean.
Unlike sports such as football, where the traditional wagering is done on the “spread” (i.e., you give or take points from the actual final score, based on the favorite), in baseball wagering, you’re simply wagering on the winning team.
The favorite in a baseball odds line has the minus sign by their line, while the underdog has the plus sign. What that means, in the context of your example, is that, if you want to bet on the favorite, Boston (-170), to win, you have to wager $170 in order to win $100 if they win the game. Conversely, if you want to bet on the underdog, Toronto (+150), by betting $100, you would win $150 if they win.
Those sorts of odds are only related to the wagering on the game; they have nothing to do with the score of the game, or any other events in the game, other than the win/loss outcome.
My understanding (which is very limited),
A bet of $100 on Toronto would pay off $150 if Toronto wins.
But you have to bet $170 on Boston, to get a $100 pay off if Boston won.
And wouldn’t +150 / -170 imply an extremely large house take?
About 3% which would be very low.
170/270 = 63%
100/250 = 40%
The overround is 3%. I think it’s usually more in the 5% range, if there is no other commission or charge.
Both @Sooner and @kenobi_65 are correct, as Sooner stated:
A correction on kenobi’s post:
Baseball also has ‘spread’ betting, in addition to betting on who wins the game. For instance, right now I’m looking at DraftKings, where I am a user.
In tonight’s Washington/LAD game, the Dodgers are favored by 1.5 runs. The betting line reads:
Nationals +1.5 +100
Dodgers -1.5 -120
So if you bet 120 bucks on the Dodgers, you are betting that the Dodgers will win by more than 1.5 runs, and if they do, you will win $100.
If you bet 100 bucks on the Nats, you are betting that they will lose by less than 1.5 runs (or win the game), and if they do, you will win $100. (In this case, that’s an even-money bet.)
But if you want to bet strictly on who wins the game, that’s the money line bet:
Nationals +205
Dodgers -245
You will have to bet 245 bucks on the Dodgers to win 100 bucks if they win the game, while a 100 dollar bet on the Nats would win you 205 dollars if they win the game.
Clear as mud?
nvm…cc
A good tip is to set the odds to “European”. That will then show the total return as a straight multiplier of your bet. (Even money would be 2.0 for example). Much simpler and much more easy to figure out.
That’s exactly what I do on the DraftKings app/website. It would be nice if it were also done that way on TV, like when the OP saw the odds.
Is there a difference between “betting” and “wagering”? I always thought that the two terms were synonyms, with “wagering” simply being a fancier word for “betting”. But @kenobi_65 seems to use “wagering” as a term of art, possibly with a defined technical meaning different than that of “betting”.
Not as far as I know. I just used “wager” a few times in my post so I didn’t have to use “bet” 10 times in one post. 
Edit: upon looking at a bunch of websites asking about the difference, it appears that there is a technical distinction. If I’m understanding what I’m reading, in a wager, you put up your money (your wager) on the outcome of the event ahead of time (which is how pretty much all sports gambling books work), while in a bet, it’s technically a contract between two parties, which is paid out after the outcome of the event in question is known – in other words, there’s no money put up front in a bet, unlike in a wager.
But, in casual parlance, the two terms seem to be interchangeable.
Thanks all. Let me make it clear that I am not looking at their site (nor would I), only at their ads and I got curious what they meant. Now I know.
So you can bet the farm, but cannot wager it.
Ignorance fought, once again.
Its best to not involve the farm. If you bet the farm, lose and do not turn it over, you then risk buying the farm. Its all very confusing.
Oh, well, at least the Toronto baseball fans are not wearing brown paper bags to hide their faces, like Toronto hockey fans used to. 