Wager your friends.
Nobody takes a cut.

The same arithmetic works on lopsided markets. A game a book posts at −280/+230 is really a 71% chance against 29%, which is a fair price of ±243 — one number, symmetric, no margin hidden on either end. Every side in the app shows both: the Vegas price, then the vig-free chance underneath it.

1. 1

   Get an invite

   OtherSide is invite-only: you join with a link from someone already in. The link gets you in the door — it doesn't connect you to anyone. Once you're here, add friends by sending a request, and they accept. The quickest way to find the rest of a group is to open a friend's name and add the people they already know. You only ever match against people on your friends list, so nobody outside it ever sees a pick of yours.

2. 2

   Pick a side and a number

   Go down the week's slate and take the sides you like: spread, moneyline, total. Say what you'd risk on each. Nothing is committed yet — it's an open interest, and you can pull it any time before a handshake is mutually agreed upon.

3. 3

   OtherSide finds the other side

   When a friend takes the opposite side of the same game, same market, same number, it shows up on your Matches page. It sizes the handshake at the largest amount you both actually have open, so 50 against 30 shakes on 30 and leaves your other 20 sitting there for someone else.

4. 4

   Shake on it

   One of you proposes, the other confirms. Both sides, or it didn't happen — until your friend confirms, nothing is live. After that it's a handshake, and it stands. Final scores land on their own and grade it.

Two details worth knowing, because they protect you rather than the app. Once you both shake, the line and the odds are locked in, like a bet slip at an online sportsbook, so a number that moves afterwards can never quietly change a wager you agreed to. And your open interest isn't reduced while a proposal sits unconfirmed — two friends can't both consume the same 50.

The app tracks a number. What that number is worth is between you and your friends, and so is squaring up — that happens wherever you'd normally settle with a friend, entirely off the app and entirely on your own terms. OtherSide's job stops at knowing who agreed to what, and who was right.

That's a deliberate line, not a missing feature. Holding or moving funds is what makes something a sportsbook, with the licensing that comes with it. Staying on this side of the line is what lets a group of friends run the whole thing with no rake at all.

Because each side already put up its fair share, that split falls straight out of the numbers you shook on — and it makes every handshake worth exactly zero on expectation. You can't climb by only backing favorites, and you can't climb by betting big. The only way up is being right more often than the market is.

What the app does instead is keep the record straight. Every handshake is timestamped and confirmed by both people, at stakes that were on screen before either of them agreed. Nothing is ambiguous afterwards, and nothing quietly disappears. Between friends, that's usually all the enforcement anyone needs — a group chat settles what a contract would.

If that ever stops being true, some kind of reliability rating is the obvious next thing to build. It doesn't exist yet, and the hope is it never has to. Invite people you'd lend money to.

There's nothing to pay today. If that changes, think of a streaming subscription, only smaller: something like $5 or $10 a month to cover the odds feed and the hosting, with maybe a little left over to make it worth building properly. It will never be anything onerous.

What it will never be is a percentage of what you wager. Charging for the introduction would just be the vig again, wearing a different hat.

Can I shake with someone who isn't on my friends list?

Not until you add them. If they're already on OtherSide, open a friend's name to see who they know, or find them by their handle on your Friends page, and send a request. If not, send them an invite link, then add them once they've joined. Once they accept, you're friends, and from then on you can see each other's open picks and shake on handshakes. What you can't do is shake with a stranger: OtherSide only pairs you with people on your own list, so a friend of a friend can ask to be added but never sees a thing you have open.

Why isn't there a password?

Because a password would be the weakest part of your account and the only part of it we could lose for you. You sign in with Google, or a code we email you, and you can add a passkey — Face ID or a fingerprint — once you're in. The Signing in page goes through all of it, including exactly what Google does and doesn't tell us.

Do other members see my real name?

Only if you want them to. Set a handle on your profile and everyone sees @handle instead of your name and photo — on your friends' lists too. People can always find you by your handle; finding you by your full name is something you switch on. Your friends can see who else you're friends with, which is what makes a group easy to join; that one is on by default and switches off on the same page.

What if the line moves before we shake on it?

Lines keep moving with the market right up until you shake on it. Once you both confirm, the number and the odds are locked in, just like a bet placed at an online sportsbook, and nothing the market does afterward touches it. One wrinkle: an open pick holds the number you picked it at, and only pairs with a friend who picked that same number. If the line moves and you still want in, pull your pick and pick again at the new number.

Are the lines live?

No. OtherSide pulls consensus lines twice a day, morning and late afternoon ET, so what you see can differ from what the books are showing right now, especially close to kickoff. Every game card says how long ago its lines were refreshed.

Can I get this on my phone?

There's nothing to download — OtherSide is a website, and on Android or a laptop the browser you're reading this in can already buzz you when a friend takes the other side. iPhones have one extra step, because Apple won't deliver a notification to a Safari tab: you add OtherSide to your Home Screen first, then turn push on inside it. There's a page of pictures for every step of that — the “On your iPhone” link at the foot of this page — and it takes about two minutes.

Can I back out?

Pull an open pick any time; withdraw a proposal any time before your friend confirms. Once you've both confirmed, it stands. That's the whole idea of calling it a handshake.

What if we only want different amounts?

It shakes on the biggest number you can both cover at the fair price, and the remainder stays open for someone else.

How does anything settle?

Final scores come in on their own and grade every confirmed handshake. Ties and exact numbers push, and a push moves nothing.

Can I bet next week's games now?

Not yet. For now it's the current week only: that's the only week whose lines get refreshed, so a future week would show you a stale number. Next week's lines post Tuesday. Opening up the week ahead is something we could add later.

What sports can I bet on?

The NFL today. College football and the Premier League have tabs of their own on the lines page, marked “soon”: both are built and tested end to end and are waiting on the odds feed rather than on any code. When they switch on they will share the same friends, open board and standings as the NFL. One wrinkle worth knowing in advance: Premier League matches will carry the handicap and the total but no moneyline, because a draw leaves a straight home-or-away pick with no honest winner. After those: MLB, the NBA, the NHL, and more of the big soccer leagues.