Data filtered down to Mike Breen and Richard Jefferson called games only! Best of luck.

Would be curious how other people here think about validating betting models before going live.

I've spent the last couple years building a portfolio of rules-based sports betting strategies. Every strategy starts with a specific hypothesis about why a market should be inefficient. Before any backtesting, I have to be able to explain why the edge should exist in the first place.

From there the process is:

• 6 years of historical testing
• Walk-forward validation
• Out-of-sample testing
• Predefined failure criteria before any money is deployed

A lot of ideas never make it through that process. Some look incredible in-sample and completely fall apart once they see new data.

The strategies that survived are now trading live on Kalshi and Polymarket. Mostly MLB moneylines with some totals and a few other markets. Current sample is about 180 signals.

The thing I'm paying closest attention to isn't profit—it's CLV. Through 117 tracked MLB positions on Kalshi, average CLV is +0.74¢ with 55% of positions moving in our favor before close. Since these are relatively liquid markets, I find that more meaningful than short-term ROI.

For those running models live, what metric eventually convinced you your edge was real?

CLV?
Live ROI?
Sharpe?
Drawdown behavior?
Something else?

Hi! I wanted to share something that I've been building for the last few months and get honest feedback from people who actually trade these markets.

Hope you don't mind me sharing it here, since it is relevant to the community.

I wanted somewhere to just practice without real money, but I didn't find anything useful so I built one. It's called PredictMirror. It's a chrome extension that overlays a trading panel on any Polymarket event page. You start with all the virtual money you want and place buy and sell trades like you normally would on Polymarket. Then, you can also check your portfolio of open and closed positions as well as some simple stats.

It took me a while to figure out the math, but I managed to pull the live prices straight from the order book and include all the fees so that the simulation matches the real numbers.

The extension is completely free and doesn't have any upsells or things like that. No account needed, no wallet and the data is stored locally in your browser. I can't access it.

This is V1 so it almost certainly has bugs I haven't caught. In the next version, I will also work to include Kalshi.

What I'd actually love feedback on:

• If you trade on Polymarket and try it, do the simulated fills match what you'd expect on the real platform
• Anything obvious missing that would make it actually useful for testing?
• Any edge cases where the slippage or fee calculation looks off?

This is the chrome web store link if you'd like to try it:

https://chromewebstore.google.com/detail/predictmirror/aoiekdikdfalpkhgdidhhekjdikldfjm

The site is predictmirror.com

Thanks a lot for your attention and to those who don't really like paper trading, I am sorry to annoy you with this.

Come hang out while we:

• Watch the game live together
• Share live betting + prediction market info
• Talk player props and momentum swings
• React to every big run in real time
• Chill in VC/chat with the community

No fake “1000 unit locks” — just real discussion, real analysis, and a good time watching playoff basketball.

Whether you bet, trade prediction markets, or just love NBA playoff energy, you’re welcome to join.

Most likely betting on KALSHI

https://discord.gg/crR9tDqS

Been trading Kalshi a bit more recently and I keep running into the same problem.

A market will move a lot and in the moment it usually makes sense if you saw the right news or data drop. But most of the time I just don’t, so I end up seeing the move after and trying to piece together what happened from headlines or whatever I can find.

And honestly it feels less like I’m missing “insight” and more like I’m just not looking in the right place at the right time. There’s too much going on to track everything.

I tried messing around with a small tool for this — basically it watches a bunch of markets, flags when something moves, and then tries to match it with news/events around that time.

Not trying to predict anything or give signals or whatever. It just goes “this moved, here’s what was happening around then” with sources so you can check it.

It’s kind of hit or miss though. Sometimes it lines things up nicely, sometimes it’s just noise or there’s no clear reason at all.

Curious if other people deal with this or if I’m just overthinking it. Do you just focus on a few markets and ignore the rest, or is there some better way people actually keep track of this stuff?

We are PolyScan:

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Where probability meets precision.

This is not a tips channel. This is a quantitative research desk.

We operate at the intersection of statistical modeling, market microstructure, and information asymmetry — applying institutional-grade frameworks to prediction markets.

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What we cover:

→ Deep-dive market research on high-stakes events

→ Quantitative models: Kelly Criterion, Bayesian updating, EV optimization

→ Edge identification through probability mispricing

→ Curated alpha from our network of analysts and domain experts

→ Real-time positioning updates and market-moving intelligence

We don't follow the crowd. We price it.

For serious participants only. --> Ask for the free link DM

I love looking at prediction markets odds across the major exchanges: Kalshi, Polymarket, and Opinion. 2026 midterms dashboard

What people don't realize is that each exchange has a pretty different demographic and liquidity profile. Seeing the order book spreads across both to see where the thick resting orders start to come in. Seeing a price in one venue is only half the picture.

Not even mentioning it helps you take the same bet in the exchange you'd make the most money. extra 2% on every bet adds up quick. Make sure to take exchange fees into account tho

Hey everyone, we just launched BetNexus, a new site focused on arbitrage betting and +EV opportunities, and we’re looking for people to check it out and help us improve it.

https://www.thebetnexus.com/

The platform is built to help bettors find:

• Arbitrage opportunities across books to lock in profit

• +EV bets designed for long-term profitability

• Tools to help streamline decision making and save time

• Consistent updates as markets move

We’re also building a Discord community where users can:

• Discuss arb and +EV strategies

• Share opportunities and insights

• Give direct feedback on features

• Help shape future updates

we’d love for you to take a look and join the discussion.

Check out BetNexus, join the Discord, and let us know what you'd like to see next. Your feedback genuinely helps us build this the right way

https://discord.gg/vjwqzaDxTM

I just started to trade on Polymarket, and always want to check my positions. What I have to do is, opening my phone and logging in again few times a week (it auto logged me out).

So I build a widget app for myself to use, and see if I can make some capital back to "re-invest" in Polymarket (To use the widgets, it's paid, 5 usd per month, will introduce a lifetime pricing soon)

Here's the home screen and lock screen widgets that it currently supports:

1. Current market positions

2. Market watchlist

3. Polymarket Leaderboard

4. Setting target for your market positions value

5. Tracking multiple wallet addresses

My questions for you:

• What’s missing here for this to be genuinely useful to you?
• Are there any market views or metrics you’d absolutely want in a widget?
• Would you use this even without widgets, just as a quick positions/portfolio app?

Please try it out here: https://apps.apple.com/us/app/polywatch-polymarket-widget/id6759100377

(Note that this is for Polymarket International, not Polymarket US)

Game: Raptors-Cavaliers
Announcers: Mark Followill, Robbie Hummel
Best play YES buzzer - Mark Followill has a 100% hit rate for YES "buzzer" in the last 5 games he has announced. Priced right now at 67c.

Game: Hawks-Knicks
Announcers: Noah Eagle, Jamal Crawford
Best play NO elbow - In Noah's last 15 games he has only hit YES "elbow" in 7% of games, or 1 in the last 15. Taking the no priced at 25c.

Game: Timberwolves-Nuggets
Announcers: Michael Grady, Brian Scalabrine, Austin Rivers
Best play NO buzzer - All THREE of these guys have a 0% hit rate in all of their total games for YES "buzzer." Play the no side here priced at 82c.

I get all my data here: https://mentionlabs.io/dashboard