How D.O.P.E. price history works
What our price history records, where you'll see it, how the Deals page uses it, and what it can't tell you.
A price on its own doesn't tell you much. Is it a good price, or the same price it's been all month? D.O.P.E. is how Price Dope answers that question.
What D.O.P.E. is
D.O.P.E. stands for Data On Previous Engagements. Among shooters, DOPE means your record of settings and conditions from previous shots, used to make the next one count. Ours is a record of previous prices.
Every offer we track, meaning one retailer's listing for one product, builds its own history over time.
What gets recorded
We save a price-and-stock entry:
- whenever an offer's price changes,
- whenever its stock status changes, and
- on any check that comes at least an hour after the previous entry.
Each entry records the listed price and the stock status at that moment. Like everything else on Price Dope, it's the listed product price. Shipping, taxes, fees and coupons are set by the retailer and may not be included.
Where you'll see it
On product pages
The price history chart on each product page shows the lowest price we recorded across retailers for each day. It's a quick way to see whether today's best price is typical, unusually low or higher than usual.
On the Deals page
The Deals page uses D.O.P.E. to find recent price drops. The rules are strict on purpose:
| Rule | What it means |
|---|---|
| Last 30 days | Only drops from the past 30 days are shown. |
| Two real records | A drop needs two actual entries in our history, one before and one after. We never estimate one. |
| Still current | The lower price must still be the offer's current price. |
| Minimum size | Changes smaller than 1% or $0.50 are skipped, since they're mostly rounding noise. |
| Sanity check | "Drops" larger than 90% are ignored. Those are more likely data errors than real deals. |
The Deals page also has a list of the lowest in-stock cost per round for popular calibers. That list comes from current prices, not history. See Cost per round, explained.
How D.O.P.E. fits with "last checked"
History and freshness work together:
- Every offer shows when it was last checked, meaning the last time our system confirmed it in the retailer's data.
- Offers that haven't been re-checked in 48 hours are marked Stale.
- Offers that haven't been confirmed in 7 days are removed from rankings, price lists and Deals.
So the price you see is recent, and the history behind it shows how that price compares with what came before.
What D.O.P.E. can't tell you
Using it when you shop
- Check the context. Before jumping on a "sale," look at the chart to see how the price compares with recent days.
- Confirm before you buy. Prices change often. Check the "last checked" time and the final price on the retailer's site, including shipping and tax.
For the full methodology, see How it works and our editorial and ranking standards.
Common questions
What does D.O.P.E. stand for?
Data On Previous Engagements. It's Price Dope's record of the prices and stock status we've seen for each offer.
How often is price history recorded?
We save a price-and-stock entry whenever an offer's price or stock status changes, and again on any check that comes at least an hour after the previous entry.
Why does a product have little or no history?
History starts when we begin tracking a retailer, so newly added products and retailers have little or none at first. It builds as we keep checking.
Can D.O.P.E. predict when prices will drop?
No. D.O.P.E. shows what we've recorded. It isn't a forecast.
How does the Deals page decide what counts as a price drop?
It looks at the last 30 days. A drop appears only when two real records support it and the lower price is still the current price. Changes smaller than 1% or $0.50 are skipped, and drops larger than 90% are ignored because they're more likely data errors.
Prices shown come from connected retailers' latest checks and change often. Price Dope doesn't sell anything and may earn a commission from retailer links. Disclosure · How we collect prices · Editorial standards
