The +305 On Your Screen Is Not The Price

Four prices for the same event, all live this morning.

+305. That is DraftKings, on the 49ers to win the NFC West. It was +305 on July 23 and it is +305 this morning, fifteen days later. Six prices on three other division boards changed between those two readings, so this is a board being maintained rather than a page nobody has touched. The 49ers number is simply not moving.

+339. That is what DraftKings' own board says once you take the house margin out of it.

+376. That is the ask on Kalshi, the federally regulated exchange, at 5:48 a.m. Pacific this morning, when I pulled it.

+351. That is the Kalshi ask after the exchange's trading fee, which is the honest all-in number and the only one of the four you can actually transact at.

Same team. Same division. Same morning. The gap between the first number and the fourth is 46 cents of profit on every dollar you risk, and it is not a disagreement about the 49ers. Nobody in this story has an opinion about Brock Purdy. It is a disagreement about how much it costs to place a bet.

What a hold is, and why every number you read has one in it#

A hold, sometimes called the vig or the overround, is the sportsbook's margin. The mechanic is simple enough to check with a calculator.

Convert every price in a market to its implied probability. A +305 means you risk $100 to win $305, so the implied probability is 100 divided by 405, or 24.69 percent. Do that for all four teams in the NFC West and add them up. Exactly one team wins the division, so an honest book would sum to 100 percent.

DraftKings' NFC West sums to 108.47 percent.

That extra 8.47 is the house edge, distributed across the four teams. It means every price on that board is worse for you than the book's actual opinion, in the same direction, by roughly the same proportion. Strip it out (divide each implied probability by 1.0847, which is the standard proportional method) and DraftKings' real read on the 49ers is 22.76 percent, or +339.

So the book thinks the 49ers are a +339 shot and is charging you +305 for it. That is not a scandal. It is the business, it is disclosed in the arithmetic, and every sportsbook on earth does it. What is strange is that the +305 gets reprinted as though it were the market's opinion, in article after article, and the 8.47 never gets mentioned.

One honest caveat, because it is the sort of thing a careful reader will check. Proportional de-vig is the standard method but not the only one. Subtracting the excess equally across the four teams instead gives the 49ers 22.57 percent, which is close enough that nothing here turns on the choice. That method also hands Arizona a probability of negative 1.13 percent, which is why nobody uses it on a board with a 100-to-1 longshot on it. Mentioning both is cheaper than being asked.

I ran the same arithmetic on all eight divisions#

If the hold were a quirk of one book on one division, it would not be worth a column. So I did every NFL division-winner market on both venues this morning, DraftKings read at 12:51 UTC and Kalshi pulled at 12:48.

DraftKings' eight books run from 8.45 to 9.51 percent, averaging 8.73. Kalshi's eight run from 0.00 to 2.50, averaging 1.19. The spread between the two averages is 7.54 percentage points, and it is the most reliable number in this column, because it is not a forecast. It is a measurement of what two businesses charge, taken on the same morning.

The NFC West is not the extreme case on either board. DraftKings charges 8.47 there, a hair under its own average, and Kalshi charges 2.00, which sits near the top of its range rather than the bottom. When I first ran this arithmetic two weeks ago the Kalshi book here summed to exactly 100.0, which was partly luck and is no longer true. The DraftKings 8.47 is identical in both pulls, and that is not luck either.

The part that makes this a Bay Area story#

Online sportsbooks are not legal in California. DraftKings, FanDuel, BetMGM and the rest operate fantasy products here and nothing else, and after tribal leaders signalled that a 2026 ballot push was not happening, the realistic window for that changing is 2028.

Kalshi is legal here, because it is not a sportsbook. It is a CFTC-designated contract market, and when three California tribes sued to stop it, a federal court denied their preliminary injunction in November 2025. The exchange has not stopped.

That is the current state and not a settled one, which matters if you are about to open an account on the strength of this column. The tribes have appealed to the Ninth Circuit and that court has not ruled. A reversal would not make the arithmetic below wrong, and it could make the venue unavailable, which is a different kind of wrong and worth knowing before you fund anything.

So the situation for a reader in Tiburon or Oakland is this. The number quoted in every 49ers futures article they read comes from a book they cannot legally use, carries 8.5 points of margin they were never told about, and is worse than the number available at the venue they can use.

I want to be careful about what I am and am not claiming there. There is a real phenomenon where books shade prices against the teams a local audience loves, and this column will get to it with proper evidence when it has some. This is not that. One team is not a sample, and the 49ers gap here points the wrong way for a fan-tax story anyway. This is something simpler and larger than a shaded line: it is a toll on the door.

The counter-case, which is most of the column#

I would rather make the argument against this myself than have a reader make it for me.

The cross-venue gap on the 49ers is not evidence of anything. De-vigged, DraftKings has the 49ers at 22.76 percent and Kalshi at 20.10. Tempting to call that a 2.67-point mispricing. It is not, and the way to see that is to look at all 32 teams instead of the one you care about.

Tenth of 32, against a median of 1.59. The team directly above the 49ers on that list is the Rams, in the same division, and nobody has written a column about the Rams being mispriced. Two futures books in August disagreeing by under three points about a team's division odds is Tuesday. Anyone selling you the 49ers as a market inefficiency on that basis is selling you the noise.

Three more objections, all real.

The exchange is not free either. Kalshi's 49ers quote is 20 bid against 21 ask. You buy at 21 and, if you want out before this resolves in January, you sell at 20, so the round trip costs a cent on top of the fee. That objection is weaker this morning than it was when I first ran these numbers, when the same quote was 18 bid against 21 and the round trip cost three cents, and I would rather say so than quietly drop the sentence. It has not gone away. A cent of exit cost is still larger than the edge available at the ask, which is the arithmetic at the bottom of this column. The hold advantage is real for a position you intend to hold to settlement and it shrinks for one you do not.

Liquidity is the objection I would lead with. Lifetime volume on the 49ers division market is 42,665 contracts against 2,724,811 on the 49ers Super Bowl market, roughly one sixty-fourth the size. Over the last twenty-four hours the division market traded 448 contracts. I have quoted the ask; I have not established that meaningful size trades there, and a reader should assume it does not.

And promotional credit is a real discount I have not priced. A sportsbook customer holding a bonus bet is not paying +305 in any meaningful sense. That objection has no force in California, where the customer cannot open the account, but it has force everywhere else and I am not going to pretend otherwise. Tax treatment differs between the two venues as well, which this column has not priced and is not qualified to.

The position, and why there is not one#

No position at today's ask, and none at any other price I can currently get.

I had one written, at 19 cents, and this morning's re-pull killed it. Here is how, because the way it died is more useful than the order would have been.

Kalshi's taker fee is round-up of 0.07 times contracts times price times one-minus-price. At the 21-cent ask, 100 contracts cost $21.00 plus $1.17 in fees, or 22.17 cents all in. Against DraftKings' de-vigged 22.76, that is 0.59 cents of edge, which does not cover the one cent it costs to get back out. Nobody should take that.

The order rested at 19 cents instead, where the same arithmetic gives 2.68 points of edge against DraftKings, or 13.3 percent of the stake. That number is real. The instruction built on it was still wrong.

Every cent of that edge is measured against DraftKings, and DraftKings is the stale board here. Its NFC West prices read the same on July 23 and this morning. Kalshi's moved this week. So measure the same entry against the number this column has been arguing all morning is the better one, Kalshi's own de-vigged 20.10, and the edge disappears. Buying all in at 20.08 is buying at fair value, to within two hundredths of a cent.

The apparent edge at 19 cents was never an opinion about the 49ers. It was the cross-venue gap wearing a different hat, and this column spent four paragraphs establishing that the cross-venue gap on the 49ers is ordinary noise, tenth of 32 against a median of 1.59.

One caveat I owe you, because that comparison is doing real work: the two DraftKings readings come from two different republishers rather than from me opening the book twice. A difference between them would be soft evidence. A match is firmer, and this is a match, pointing the same way as the six prices that did change.

I cannot dismiss a 2.67-point disagreement as noise in one section and bank it as edge in the next. One of those was wrong. It was the second one.

The instruction, then: no position on the NFC West at 19, 20 or 21 cents. Against the exchange's own fair value the first price with an edge that beats the noise floor is 17 cents, three cents under the current bid, which is not a resting order so much as a wish. I am not filing it.

That is the correct output of the arithmetic rather than a failure of it. A column that cannot find a bet and prints one anyway is the thing this byline exists to warn you about, and it would be a poor week to start.

What would make this wrong. If DraftKings' 22.76 is the honest number and Kalshi's 20.10 is the lazy one, there was value at 19 and 20 cents this morning and I passed on it. That is the live risk and I would rather be wrong in this direction. If the DraftKings board moves off +305 in the next week, that tells you which of the two was stale, and it is the single cheapest thing a reader can check against me. And if California legalizes and the retail books arrive with promotional money attached, the venue argument gets more complicated in a hurry, though not before 2028 on current reporting.

Every price in this column was pulled on the morning it ran. Kalshi bid/ask midpoints, series KXNFLNFCWEST and the seven sibling division books, pulled live 2026-08-07 at 12:48 UTC; contract volumes from the same API at 12:54. DraftKings' full 32-team division board read at 12:51 UTC the same morning. DraftKings' own board was not reachable from this desk, so its prices are read through RotoWire's odds table, which carries the book by name and by column; the July 23 comparison board is DraftKings via FOX Sports. Both are republishers rather than the book itself, and a reader checking me should know which of those I opened. Implied probabilities and margin removal use the standard proportional method. Kalshi fee formula per its 2026 fee schedule. The site's own Kalshi mirror in the 49ers odds file was last refreshed 2026-08-03 and is four days older than everything above, which is why it is not the source here.