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- Issue #53
Sports Betting: July 21 - 27, 2025
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Irvin’s main punchouts are his four seamer, sinker, and curveball.
He tends to be more fastball driven versus righties and today we have the Reds showcasing at least 5 of them.
With the Reds tendency to go for GB’s in this spot, we are trying to avoid Irvin’s curveball here, which I think we could get less volume of with the edge of the Reds having more righties on display.
Also, Irvin tends to rely on location since he has a low whiff and chase rate overall.
The Reds are aggressive as they come with a low BB% against righties so I think they’ll come out tonight to challenge Irvin who also tends to throw a high percentage of meatballs in the zone.
We want lots of contact tonight and I think we have a shot here with Irvin.
Give us the UNDER!
Friedl is as consistent a hitter as they come - he’s only gone on ONE hitless streak of 4 games or longer in his past 3 years.
If he fails to get a hit tonight it will be his second time, but I find that unlikely against Jake Irvin.
Friedl excels against righties and tends to be even more consistent in away games, and batting in the one-spot against a team with streaky pitching helps his case even more.
On the other side, Jung Hoo Lee will bat the leadoff position against Bryce Elder, who has given up 92 hits in 79 innings (~1.16 HPI).
The first time these two faced each other Bryce Elder was having the game of his life, going 5 innings on 3 hits and racking up 12 strikeouts.
Lee is a strong hitter and should get the best of Elder in this matchup.
I have 2 units on this play myself, and find this playable up to -115.
I emphasize this because Cameron’s command also tends to falter versus righties as he’ll throw off the zone (Cubs are projected to have 7 righties tonight).
Cameron’s xFIP also drops to a mediocre 4.96 on the road versus righties.
I think overall he struggles tonight with pitching around and punching out the Cubs.
He’s been over this line in his L3 games and is due a goose egg.
Think we get it here tonight as Cameron’s road splits also tend to be lower than his home so we should have an edge here.
Median of 4.5 so a 4.5 line is worth a stab even at this price.
Give us the UNDER!
When to Increase (or Decrease) Your Unit Size
Move beyond guesswork, scale with discipline
In sports betting, your riskiest moment isn’t always when you're losing - it's often when you're winning.
Most bettors scale units based on emotion or intuition, turning disciplined strategies into risky gambles.
Professional bettors know better: unit sizing is a calculated decision, never an impulsive one.
This week, we're breaking down exactly when and how to adjust your unit size.
Unit Sizing: It’s a Numbers Game
True Edge vs. Perceived Edge
Many bettors overestimate their edge due to short-term success or confirmation bias.
Here's an example of how pros evaluate edge.
Statistical Significance Check:
100 bets at 5% ROI: 30% chance it’s luck.
1,100 bets at 5% ROI: <5% chance it’s luck (statistically significant).
Takeaway: Don’t scale up until you can statistically prove your edge.
The Kelly Criterion Reality Check
The Kelly Criterion is the mathematical backbone of unit sizing - but professionals don’t usually bet full Kelly.
They opt for fractional Kelly (25%-50%) to safeguard against edge overestimation.
Betting "full Kelly" means wagering the maximum amount recommended by the Kelly criterion to maximize long-term growth. It aims for the highest possible growth rate, but it also comes with higher risk and volatility
The Professional Framework for Bankroll Scaling
Scaling isn’t guesswork. It’s methodical.
The 20% Rule
Increase unit sizes after a 20% bankroll growth.
Example: Starting bankroll $10,000, increase from $100 units (1%) to $120 units when bankroll hits $12,000.
Conservative vs. Aggressive Scaling
Conservative: 1% of bankroll per bet.
Aggressive (but controlled): Up to 2-3%, rarely more.
Psychological Pitfalls: Dodging Cognitive Traps
Overconfidence Bias: The Silent Killer
The overconfidence effect is the most dangerous cognitive bias in betting, and shows up in a variety of forms.
Hot-streak scaling: Increasing bets exactly when variance is likely to revert.
False pattern recognition: Thinking short-term success signals long-term skill.
Confirmation bias amplification: Seeking information that confirms your betting "skill" while ignoring contradicting evidence
Professional Counter-Strategy
Keep detailed records.
Scale only where your edge is proven, not assumed.
Track your results by bet type, sport, and market. If your edge appears in one specific area (e.g., NBA player props), resist the urge to apply the same unit size to different markets where your edge may not exist.
Loss Aversion: Betting with Fear
Bettors prone to loss aversion do one of two things.
Under-bet when they’ve established an edge (leaving money on the table)
Over-bet when chasing losses
It's exactly why setting predetermined scaling rules and sticking to them is essential for any bettor.
Especially during emotional highs and lows.
Variance Management: Embracing Reality
Professional bettors expect variance and plan for it - You should too.
If you flipped a coin 10 times and it lands on heads 7, it doesn't mean tails is less likely to occur. Just like if you flip a coin once and it lands on heads, that doesn’t mean it's bound to land on tails on the next flip.
Even with a consistent 5% edge and disciplined betting (1% per unit), drawdowns of 15-25% are mathematically expected over time.
Accept variance as normal, not as failure.
Risk of Ruin Framework
Your unit size directly influences your risk of ruin:
1% units: Virtually zero risk with a confirmed positive edge.
3% units: Acceptable only with significant, proven edges.
5%+ units: Typically too risky unless edge and bankroll justify it.
The more money you risk on each bet directly correlates to how much variance you can handle.
Even the best bettors in the world go on losing streaks, but they have a bankroll management plan and the discipline needed to ride it out.
Signs You’re Ready to Scale Up
1,000+ bets: Proven, statistically significant edge
ROI: Sustained for at least 6 months, the longer the better
Bankroll: Growth of 20%+ from betting (NOT new deposits)
Process-focused rather than results-oriented
Consistently beating closing lines (CLV)
Red Flags: When to Scale Down
Negative ROI sustained over 200+ bets
25%+ drawdown from peak bankroll
Loss of previously identified edges
Behavioral Indicators:
Chasing losses
Emotional or impulsive betting
Inconsistent staking without mathematical justification
Decreased edge due to increased market efficiency
The Bottom Line
Discipline Beats Speculation Every Time.
Being a profitable long-term sports bettor isn't just about hitting big bets.
It’s about having the discipline to find, quantify, and exploit edges.
In a world where 99% of bettors lose long-term, disciplined bettors win by scaling intelligently, not aggressively.
Your unit size should always reflect mathematical reality, not wishful thinking.
And that's all for this week. Tap in next week to learn about a (free) bet tracking tool that caters to rec bettors, pros, and pick sellers alike.
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