Need Help From The Math Guys

**mathdotcom** · 01-12-12, 05:12 PM

I don't get your question.

You're asking, at halftime, what would be the fair odds on the following bet?

Current score at halftime: Favorite 50, Underdog 60
Favorite to win the game by 4: odds
Underdog not to lose by 4: odds

where odds would be something like +300 or so because the odds of the favorite covering -4 for the game is equivalent to the favorite winning the 2h by 14 which is unlikely and would probably be in the +300 range.

**YouMama** · 01-12-12, 05:34 PM

is this what u are looking for?

if the Fav is a -2 and the over under is 100, the Fav is expected to score 51% of the points ... if the half finished at 50, snd the Fav is down by 10, then they fav actaully scored 40% of the points.

If the 2nd half Line is -3, the Fav is expected to score 51.5% of the remaining points ... wich if the game finished at 100 the Fav would have scored 45.8% of the total game points

which is 5.2% less than pre-game expectations ???????????????????????????????????????? ??????????????????????????????????????

**PatrickBateman** · 01-12-12, 06:13 PM

The two questions posed were completely separate. The first one - When a game line favorite is losing at the half and the 2nd half line leads to an adjusted game line of the same team now a dog, how do you figure out how far off the original game line the new adjusted game line has become.

So team A is -7 pregame line. They are losing by 10. 2nd half line has team A -5. This means that team A has become a +5 dog. I want to know how you would determine the percentage change from team A being a -7 fave to becoming a +5 adjust game line dog.

Sorry if I am not explaining clearly.

The other question I am asking pertains to just the O/U, has nothing to do with the spread. Essentialy I just want to know how to determine the percentage off an original pregame O/U is from the 1st half scoring + 2nd half line

So for example if a game has an O/U of 200. The first half score is 35-32. The 2nd half line comes out at O/U 100. That leaves the new game adjusted line at 167. Does that mean the original line (taking into consideration the 2nd half) is 16.5% off?

Overall I am trying to determine what percentage an original pregame line is off when you take into consideration the 1st half score + the 2nd half line.

Appreciate the help, was hoping you two fellas would come into this thread since I recognize that you both always provide knowledgeable answers. I am guessing that my question is just so simple I am making it sound way more complicated and thats probably what is tripping you up. Thanks again

**YouMama** · 01-12-12, 07:02 PM

team A -8 pregame ... Full game score expected pregame if half total is 100 is 96-104 Team A ... Halftime actual score 55-45 Team B, but team A expected to make up 4 pts ... then new full game score expected to be 108-92 Team B ... Original line off by 6% at the half ???

cuz team A will score 46% of the points as oppsed to pregame they were expected to score 52% ????

**mathdotcom** · 01-12-12, 08:31 PM

Originally posted by PatrickBateman

I graduated with an English Degree, Math is not my strong suite. Just looking for some help determining how much a pointspread is off for the game when the 2nd half line comes out. Probably simple stuff for most of you but I am having trouble figuring out when a favorite becomes a dog per the 2nd half line.

Example- A -4 favorite is losing by 10 at the half. 2nd half line has them at -3. SO for the game they have gone from a -4 favorite to a +7 dog. Now what percentage has the line changed from the original line? I have been unsure whether or not my math was right for faves that cross over into dogs.

Also, when trying to figure out how much an O/U line is off do you simply take (1st half score + 2nd half O/U line) - the original O/U and then divide by the original O/U? Is that an accurate line to see how far the original game line is off?

Again sorry if this is rudimentary stuff but I am not a math guy. Appreciate any help.

I'm sorry. I tried to help you but ironically I cannot understand a word you're saying despite your English degree.

**FourLengthsClear** · 01-12-12, 09:19 PM

The percentage 'swing' in both cases would be calculated by the shift in push probabilities.

In the first example, the market expectation at half time might well be something like (figures pulled from thin air):

Team B wins by 11+ points: 30%
Team B wins by 8-10 points: 17%
Team B wins by 7 points: 6%
Team B wins by 5-6 points: 11%
Team B wins by 4 points: 5%
Team B wins by 1-3 points: 12%
Team A wins by 1-3 points: 8%
Team A wins by 4 points: 3%
Team A wins by 5+ points:8%

Whereas pregame the were:

Team B wins or loses by less than 4 points: 48%
Team A wins by 4 points: 4%
Team A wins by 5+: 48%

**pokernut9999** · 01-14-12, 06:37 PM

Since when did PatrrickBateman ever make a bet ?

**donjuan** · 01-17-12, 03:05 AM

Originally posted by mathdotcom

I'm sorry. I tried to help you but ironically I cannot understand a word you're saying despite your English degree.

English is his strong suite [sic].

**mathdotcom** · 01-17-12, 11:43 AM

Originally posted by donjuan

English is his strong suite [sic].