Half-Point Calculator

Calculates the value of buying or selling half-points for MLB totals and NBA, NFL, NCAA Basketball, and NCAA Football spreads and totals.

 

Inputs

  • League:
    Specifies the league of interest. Currently supports NFL, NBA, MLB (totals only), NCAA Basketball ('NCAABK'), and NCAA Football ('NCAAFB').
  • Bet Type:
    Specifies the type of bet -- either spread (for all leagues other than MLB) or total.
  • Odds Type:
    Specifies either US or decimal-style odds (if odds are improperly specified the software will usually auto-convert for you).
  • Spread/Total:
    Enter the spread or total (depending upon the bet type). Negative numbers will be converted to positive. For pick'em games, enter a zero. After this field is changed, the software will fill-in the push probabilities below using default values.
  • Fave/Over Price:
    The money line adjustment factor for the favorite (in the case of a spread bet) or the over (in the case of a total bet). If, for example, the spread market were NY Jets +3.5 -120 / New England -3.5 +100, you'd enter -120. Alternatively, if the total market were Over 42.5 +125 / Under 42.5 -145, you'd enter +125. Very frequently, this number will just be -110. Advanced usage note: If you enter a percentage in this field, the software will convert the percentage to a zero-vig price. For example, if you entered 25% in this field, the software would fill in +300 for the fave/over and -300 for the dog/under.
  • Dog/Under Price:
    The money line adjustment factor for the underdog (in the case of a spread bet) or the under (in the case of a total bet). If, for example, the spread market were NY Jets +3.5 -120 / New England -3.5 +100, you'd enter +100.Alternatively, if the total market were Over 42.5 +125 / Under 42.5 -145, you'd enter -145. Very frequently, this number will just be -110. Advanced usage note: If you enter a percentage in this field, the software will convert the percentage to a zero-vig price. For example, if you entered 66.667% in this field, the software would fill in +200 for the fave/over and -200 for the dog/under.
  • Calculate:
    Clicking this button will calculate Prices and Edges in the section below.

Outputs

  • Spread/Total:
    This column of boxes displays the spreads or totals within 1½ points on either side of the figure in the Spread/Total box above. Note that clicking the up and down arrows on the top and bottom of the grid will scroll the entire grid up or down. Important note: The calculator becomes increasingly less accurate the farther away from the starting spread/total it moves. Although the calculator allows you to examine prices more than 1½ points from the initial spread/total, doing so is not generally recommended and such values should be viewed with an abundance of caution.
  • Push Prob: also takes Input
    This column contains the probabilities of pushing against the given spread total. The calculator will supply, or if you prefer you may enter your own.
  • Fave/Over Price: also takes Input
    This column contains the payout odds (i.e., the price) on the favorite/over at the given spread/total that corresponds to the same vig as the initial payout odds. You may enter your own values in the cells to determine the juice you're paying (or the edge you're receiving) by betting at that price.
  • Fave/Over Edge:
    This column shows the juice you're paying (for negative values) or the edge you're receiving (for positive values) by betting on the favorite/over at the price in the column to the left. Advanced usage note: If you hold the mouse over a cell in this column, the implied win probability will be displayed as help text.
  • Dog/Under Price: also takes Input
    This column contains the payout odds (i.e., the price) on the underdog/under at the given spread/total that corresponds to the same vig as the initial payout odds. You may enter your own values in the cells to determine the juice you're paying (or the edge you're receiving) by betting at that price.
  • Dog/Under Edge:
    This column shows the juice you're paying (for negative values) or the edge you're receiving (for positive values) by betting on the underdog/under at the price in the column to the left. Advanced usage note: If you hold the mouse over a cell in this column, the implied win probability will be displayed as help text.

Example:

The offshore market (which you believe to be accurately reflecting the true underlying probabilities without bias) is offering the following NFL market:
Offshore Market
Tampa Bay +2½ -110 OVER 39½ +103
Carolina -2½ +102 UNDER 39½ -113
While at the same time your local is offering:
Local Market
Tampa Bay +2½ -110 OVER 39½ -110
Carolina -2½ -110 UNDER 39½ -110
Your local allows you to buy up to 3 spread or total half-points for 10¢ except on and off the 3-point on spreads where he charges 20¢.

What would represent your most profitable spread and your most profitable total that you can bet with your local?

Let's examine the spread. First, we need to set up on the top section of the calculator the 'true' market as reflected by the offfshore market.
  1. set the League to 'NFL'
  2. set the Bet Type to 'Spread'
  3. set the Odds Type to 'US'
  4. enter 2.5 in the Spread box
  5. enter +102 in the Fave Price box (the favorite, Carolina -2½ is being offered at +102)
  6. enter -110 in the Dog Price box (the underdog, Tampa Bay +2½ is being offered at -110)
  7. click calculate
Next, we enter on the bottom half of the calculator the different bets being offered by your local.
  1. Favorite (Carolina -2½):
    • for a spread of 2.5, enter -110 in the fave price box (you can bet the favorite, Carolina -2½ at -110 with your local)
    • for a spread of 2, enter -120 in the fave price box (you can bet Carolina -2½ at -110 with your local and can buy an additional half-point for 10¢)
    • for a spread of 1.5, enter -130 in the fave price box (you can bet Carolina -2 at -120 with your local and can buy an additional half-point-for 10¢)
    • for a spread of 1, enter -140 in the fave price box (you can bet Carolina -1½ at -110 with your local and can buy an additional half-point for 10¢)
  2. Underdog (Tampa Bay +2½):
    • for a spread of 2.5, enter -110 in the dog price box (you can bet the underdog, Tampa Bay +2½ at -110 with your local)
    • for a spread of 3, enter -130 in the dog price box (you can bet Tampa Bay +2½ at -110 with your local and can buy an additional half-point on to the 3 for 20¢)
    • for a spread of 3.5, enter -150 in the dog price box (you can bet Tampa Bay +3 at -130 with your local and can buy an additional half-point off of the 3 for 20¢)
    • for a spread of 4, enter -160 in the dog price box (you can bet Tampa Bay +3½ at -150 with your local and can buy an additional half-point for 10¢)
Finally, we look in the fave edge and dog edge columns for the relevant expectations:
Carolina -2½ -7.240%
Carolina -2 -9.124%
Carolina -1½ -10.536%
Carolina -1 -11.092%
Tampa Bay +2½ -1.851%
Tampa Bay +3 0.832%
Tampa Bay +3½ 2.006%
Tampa Bay +4 2.525%

This tells us that at approximate edges of 2.006% and 2.525% respectively, the Tampa Bay +3½ and +4 bets are the best. The worst bets are the Carolina -1½ and -1 bets at -10.536% and -11.092%, respectively.
Now let's examine the total. First, we need to set up on the top section of the calculator the 'true' market as reflected by the offshore market.
  1. set the League to 'NFL'
  2. set the Bet Type to 'Total'
  3. set the Odds Type to 'US'
  4. enter 39.5 in the Total box
  5. enter +103 in the Over Price box (the OVER 39½ is being offered at +103)
  6. enter -113 in the Under Price box (the UNDER 39½ is being offered at -113)
  7. click calculate
Next, we enter on the bottom half of the calculator the different bets being offered by your local.
  1. OVER 39½:
    • for a total of 39.5, enter -110 in the over price box (you can bet the over 39frac12; at -110 with your local)
    • for a total of 39, enter -120 in the over price box (you can bet the over 39frac12; at -110 with your local and can buy an additional half-point for 10¢)
    • for a total of 38.5, enter -130 in the over price box (you can bet the over 40 at -110 with your local and can buy an additional half-point for 10¢)
    • for a total of 38, enter -140 in the over price box (you can bet the over 40frac12; at -110 with your local and can buy an additional half-point for 10¢)
  2. UNDER 39½:
    • for a total of 39.5, enter -110 in the under price box (you can bet the under 39½ at -110 with your local)
    • for a total of 40, enter -120 in the under price box (you can bet the under 39½ at -110 with your local and can buy an additional half-point 10¢)
    • for a total of 40.5, enter -130 in the under price box (you can bet the under 40 at -110 with your local and can buy an additional half-point for 10¢)
    • for a total of 41, enter -140 in the under price box (you can bet the under 40½ at -110 with your local and can buy an additional half-point for 10¢)
Finally, we look in the over edge and under edge columns for the relevant expectations:

OVER 39½ -8.082%
OVER 39 -10.377%
OVER 38½ -12.146%
OVER 38 -12.734%
UNDER 39½ -1.009%
UNDER 40 -2.250%
UNDER 40½ -3.398%
UNDER 41 -2.412%

Unlike with the spread, none of these totals imply a positive expectation. If, however, you still wanted to bet on this total, your "least bad" option would be the under 39½. This is indicative of the fact that it is not generally profitable to buy half-points on NFL totals for 10¢ or more.