Betting Analysis

Quick Start

sports-skills betting convert_odds --odds=-150 --from_format=american
sports-skills betting devig --odds=-150,+130 --format=american
sports-skills betting find_edge --fair_prob=0.58 --market_prob=0.52
sports-skills betting evaluate_bet --book_odds=-150,+130 --market_prob=0.52
sports-skills betting find_arbitrage --market_probs=0.48,0.49
sports-skills betting parlay_analysis --legs=0.58,0.62,0.55 --parlay_odds=600
sports-skills betting line_movement --open_odds=-140 --close_odds=-160

from sports_skills import betting

betting.convert_odds(odds=-150, from_format="american")
betting.devig(odds="-150,+130", format="american")
betting.find_edge(fair_prob=0.58, market_prob=0.52)
betting.find_arbitrage(market_probs="0.48,0.49")
betting.parlay_analysis(legs="0.58,0.62,0.55", parlay_odds=600)
betting.line_movement(open_odds=-140, close_odds=-160)

Odds Formats

-150

+130

1.67

2.30

0.60

0.43

• American negative: prob = -odds / (-odds + 100). Example: -150 → 150/250 = 0.600
• American positive: prob = 100 / (odds + 100). Example: +130 → 100/230 = 0.435
• Decimal: prob = 1 / odds. Example: 1.67 → 0.599
• Kalshi prices (0-100 integer): divide by 100 to get probability format

Commands

convert_odds

devig

find_edge

kelly_criterion

evaluate_bet

find_arbitrage

parlay_analysis

line_movement

Workflows

Workflow: Compare ESPN vs Polymarket/Kalshi

1. Get ESPN moneyline odds for a game (e.g., from

   nba get_scoreboard

   ):
   • Home:

     -150

     , Away:

     +130

2. Get Polymarket/Kalshi price for the same outcome (e.g., home team at

   0.52

   ).
3. De-vig the ESPN odds to get fair probabilities:

   devig --odds=-150,+130 --format=american

   → Fair: Home 57.9%, Away 42.1% (removed ~3.5% vig)
4. Compare fair prob to market price:

   find_edge --fair_prob=0.579 --market_prob=0.52

   → Edge: 5.9%, EV: 11.3%, Kelly: 0.123
5. Or do it all in one step:

   evaluate_bet --book_odds=-150,+130 --market_prob=0.52

Workflow: Arbitrage Detection

1. Get the best available price per outcome from different sources:
   • Source A (Polymarket): Home team at 0.48
   • Source B (Kalshi): Away team at 0.49

2. find_arbitrage --market_probs=0.48,0.49 --labels=home,away

   → Total implied: 0.97 (< 1.0 = arbitrage!) → Guaranteed ROI: 3.09% → Allocation: 49.5% on home, 50.5% on away
3. For 3-way football markets:

   find_arbitrage --market_probs=0.40,0.25,0.30 --labels=home,draw,away

Workflow: Parlay Evaluation

1. De-vig each leg to get fair probabilities:
   • Leg 1:

     devig --odds=-150,+130

     → fair prob 0.58
   • Leg 2:

     devig --odds=-130,+110

     → fair prob 0.55
   • Leg 3:

     devig --odds=-110,-110

     → fair prob 0.50

2. parlay_analysis --legs=0.58,0.55,0.50 --parlay_odds=600

   → Combined fair: 15.95%, offered +600 implies 14.29% → Edge: 1.66%, +EV
3. If legs are correlated (e.g. same-game parlay): add

   --correlation=0.1

   — this increases combined probability since correlated events are more likely to co-occur

Workflow: Line Movement from ESPN

1. Get ESPN odds for a game — both open and close lines are available:
   • Open moneyline: -140, Close moneyline: -160
   • Open spread: -6.5, Close spread: -7.5

2. line_movement --open_odds=-140 --close_odds=-160

   → Probability shift: +3.21% toward favorite → Classification: sharp_action
3. With spread too:

   line_movement --open_odds=-140 --close_odds=-160 --open_line=-6.5 --close_line=-7.5

   → If ML and spread move same direction: sharp action confirmed → If they move opposite: reverse line movement (public vs sharp split)

Workflow: De-Vig Sportsbook Odds

1. devig --odds=-110,-110 --format=american

   → Each side is 50.0% fair (standard -110/-110 spread/total)

2. devig --odds=-200,+170 --format=american

   → Favorite: 65.2%, Underdog: 34.8%

3. devig --odds=-150,+300,+400 --format=american

   (3-way football) → Home: 47.3%, Draw: 19.8%, Away: 15.7%

Workflow: Odds Conversion

1. convert_odds --odds=-150 --from_format=american

   → Probability: 60.0%, Decimal: 1.6667

2. convert_odds --odds=2.50 --from_format=decimal

   → Probability: 40.0%, American: +150

Examples

1. devig --odds=-150,+130 --format=american

   → Fair home prob ~58%

2. find_edge --fair_prob=0.58 --market_prob=0.52

   → Edge ~6%, positive EV

3. kelly_criterion --fair_prob=0.58 --market_prob=0.52

   → Kelly fraction
4. Present: edge, EV per dollar, recommended bet size as % of bankroll

1. find_arbitrage --market_probs=0.48,0.49 --labels=home,away

2. If arbitrage_found: present allocation percentages and guaranteed ROI
3. If not: present the overround and explain there's no guaranteed profit

1. De-vig each leg to get fair probs (e.g. 0.58, 0.62, 0.55)

2. parlay_analysis --legs=0.58,0.62,0.55 --parlay_odds=600

3. Present: combined fair prob, edge, EV, +EV or -EV, Kelly fraction

1. line_movement --open_odds=-140 --close_odds=-160

2. Present: probability shift, direction, magnitude, classification (sharp action, steam move, etc.)

1. devig --odds=-110,-110 --format=american

2. Present: each side is 50% fair probability, vig is ~4.5%

1. convert_odds --odds=-200 --from_format=american

2. Present: 66.7% implied probability, 1.50 decimal odds

Commands that DO NOT exist — never call these

• get_odds

  — does not exist. This module analyzes odds, it doesn't fetch them. Use nba-data/nfl-data/etc. for ESPN odds, or polymarket/kalshi for prediction market prices.

• calculate_ev

  — does not exist. Use

  find_edge

  or

  evaluate_bet

  instead.

• compare_markets

  — does not exist. Use the

  markets

  skill for cross-platform comparison.

Key Concepts

• Vig/Juice: The sportsbook's margin. A -110/-110 line implies 52.4% + 52.4% = 104.8% total, meaning 4.8% overround. De-vigging removes this to get fair probabilities.
• Edge: The difference between your estimated true probability and the market price. Positive edge = profitable in expectation.
• Kelly Criterion: Optimal bet sizing that maximizes long-term growth. f* = (fair_prob - market_prob) / (1 - market_prob). For conservative sizing, multiply the Kelly fraction by 0.5 (half-Kelly) or 0.25 (quarter-Kelly).
• Expected Value (EV): Average return per dollar bet. EV = fair_prob / market_prob - 1.
• Arbitrage: When prices across sources don't sum to 100%, you can bet all outcomes and guarantee profit regardless of the result.
• Parlay: A multi-leg bet where all legs must win. Combined probability = product of individual leg probabilities. Higher risk, higher reward. Check if the offered odds exceed the fair combined odds.
• Line Movement: How odds change between open and close. Large moves toward one side suggest sharp/professional money. Reverse line movement (moneyline and spread moving opposite directions) suggests a public vs sharp split.