I'm thinking about "buying" the half point in the Bears/Packers game.

On Ryan's board, I saw Coast say he like the bet at 3 points, but not at 3.5 points.

Any strong feeelings/advice about buying points (in general and for the Bears game)?

I am just going by what I have learned from Coast...there are certain, critical numbers for lines. These are numbers that are frequently final point differences. If you are at the number and like a side it is a good idea to buy a half a point to put that number in your favor.

Only buy to the key numbers.
Sides: 3, 7, 10, 14.
Totals: 37, 41

Some books charge more than 10 cents juice to get on or off three and seven. I love books that only charge 10 cents to move on or off key numbers.

Anything else is a waste of money. There is a reason why the books let you buy a half point, and it isn't because they lose on it.

Parlays are a waste of money. The only time I roll out a parlay is on Sunday, if Saturday was a huge day, or in college basketball, I will parlay big money line favs.

Teasers: Never tease a college total, only sides. Never tease across zero (don't tease a 3 pt fav to a 3 pt dog). Teasers should never be a part of a long term stategy. I will only do them to cross key numbers.

Here's what Coast has to say:

To further examine your question, J, let's do the math using real NFL results from 1990-2006 of actual win percentages at certain spread and moneyline numbers. (Taken from tables in the book Sharp Sports Betting by Stanford Wong). The bottom line is that if you can buy the half to 3 for 125 or less, do it. If the cost is higher than that, you have a negative expected value. The best alternative may be to buy the moneyline.

Here is the math for your various alternatives:

1) The win probability % of NFL moneylines of -178 (roughly equivalent to -3.5, -110) is 64%. 64 times you will win $100. 36 times you will lose $178.
(64X100) + (36X-178) = 6400 - 6408 = -8
The net expected value of this moneyline bet is to lose $8 every 100 bets, or an EV of $99.92 or a -EV of $.08. That is very close to a break-even bet, but is marginally negative EV.

2) Buy a half point to -3 for 25 cents to push the total price to $135 to win $100. Historical NFL data shows that 3 point favorites were 166-130-40, or 56.08%. Under this scenario, 56.08 times you will win $100 and 43.92 times you will lose $135.
(56.08 x 100) + (43.92 x 135) = 5608 -5929.29 = -321.29
The net expected value of this bet to buy a half and pay a total of 135 is to lose $321.29 every 100 bets.

3) Don't buy the half point and stick with a bet of -3.5 at -110. Historical NFL data shows that 3.5 point favorites were 108-129, or 45.5% (See why I don't like laying 3.5?)

So if you bet $110 on Green Bay -3.5 100 times, 45.5 times you will win $100 and 54.5 times you will lose $110.
(45.5 x 100) + (54.5 x -110) = 4550 - 5995 = -1445.
The net expected value of this bet is to lose $1445 every 100 bets.

......
Now let's consider the value of being able to buy a line at 3 at -110 or -120. I know that's not an alternative for you now, but -120 on Green Bay was available earlier in the week.

4) 3 point favorites in the NFL cover 56.08% of the time. So if you bet 100 times $110 to win $100 , 56.08 times you will win and 43.92 times you will lose.
(56.08x100) + (43.92 x -110) = 5608 - 4831.20 = + 776.80.
The next expected value of betting a 3 point favorite in the NFL at -110 is to win $776.80, or a +EV of 7.76.

5) If you paid $120 on a 3 point favorite, it is +EV:
(56.08X100) + (43.92 x -120) = 5608 - 5270.40 = +337.60, or a +EV of 3.37.

6) At -125, buying the half point to 3 becomes a marginal +EV
(56.08 x 100) + (43.92 x - 125) = 5608 - 5490 = +118 = EV +1.18

7) At -130, buying the half point becomes a -EV bet
(56.08 x 100) +(43.92 x -130) = 5608 - 5709.60 = -101.60 = EV - $1.01

........
So, the bottom line of all this is that if it costs you $130 or $135 /100 to buy the half point, your better option is to buy the Packers on the moneyline at -178 or less. If it costs you a total of $125/100 or less to buy the half point, do it.

......

I don't think it is ever a good idea to knowingly make a -EV bet. Thus, I should have said that it makes sense to take the moneyline (rather than a -130 or -135 buy) if you can get it for LESS than -178. At -177 ML, the win percentage is still 64%, but the $1 difference in price makes it a +2.8 cent EV, rather than a -8 cent EV.

.....

The data I gave you above relates to home team favorites of -3. That is the case with this week’s Green Bay – Chicago game. If you go through the data for both home favorites and road favorites and all the possibilities and outcomes for 2.5, 3 and 3.5 point spreads, the bottom line is this: There are four situations for which it is worthwhile paying -125 or less to buy a half point: to go from -3.5 to -3, to go from -3 to -2.5, to go from +2.5 to +3 and to go from +3 to +3.5.

Buying half points on other numbers
Some books charge only 10 cents to buy a half point. If your book charges more than 10 cents, then there is no other situation in which you should buy a half-point in the NFL. If your book charges you only 10 cents to buy a half, then there are a few other situations worth considering:

If the spread is 7 or 14, the game has been ending in a push about 6% of the time. If you can buy a half point for ten cents to gain a tie or a win on the 7 or 14, you should consider buying the half point. It is a marginally +EV. If you have to pay more than ten cents, don’t do it.

Buying a half point for ten cents when the spread is 17 (5% push rate) is approximately break-even. If you have to pay more than ten cents, don’t do it.

It is not worth paying ten cents for a half point on any numbers except 3,7,14 and 17.

One final note: this analysis only applies to the NFL. It does not apply to college or any other professional football spreads.

I was told there'd be no math.

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You know me like that.

Save your money and never buy the half pt. Sucker bet just like insurance in blackjack. How many times does that half pt actually make a difference? If you dont want to lay 3.5 and thats the only line you can get then just stay away.

Don't listen to that advice.

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Fire Phil Emery