Well, firstly, never ever EVAH EVAH take a listicle on the internet as an authoritative source.

The problem with calculating wealth, richest, and biggest hauls is hard to determine because of lack of record keeping and/or lost records, having to do fuzzy math based around currency exchanges, inflation, and cost of living. It's hard to say who is the "winner" of the richest pirate and to top that off, you have to probably lump pirates and privateers together, which would make pirate enthusiasts quibble with privateer enthusiasts as they're actually quite different things.

The issue with Avery's capture of the Mughal's boat, Ganj, is the discrepency over the Mughal's claim and the BEI estimates. I mean, we have to deal with an insurance claim here, and as you can tell, since the dawn of insurance there has been dispute, lol.

The Capo, is a stronger contender for best haul. As for Bellamy his Whydah, probably doesn't come close.

You also have Sir Francis Drake who was a Sea Hawk (privateer...a.k.a contract pirate), who while not capturing a ship, did capture the Spanish Silver Train in 1573, where he took so much silver that he honestly couldn't carry it all away! Estimates put drakes take at about 20 million pounds in todays money but this page which is dedicated to the study of Drake shows that roughly half a ton of gold was captured, and they buried 15 tons of silver.

What's interesting to note is that silver was a commodity that was almost completely controlled by the Hapsburgs in Europe, as the largest mining operations for Silver in Europe was at the time controlled by them, as well as the silver mines in Potosi, Bolivia which put out so much silver it changed the entire currency system of Europe and caused inflation on the whole continent!

It's fundamentally never been easy to ballpark the relative currency exchanges and additionally, the market prices for the goods taken such as silk, sugar, tobacco, manufactured iron goods, porcelain, etc., could vary over time and markets (for example certain spices in India were vastly cheaper there than in Italy or Spain). Don't forget they also sold their ships, slaves, ransoms, etc.

It's probably easiest to stick with the actual precious metal takes as those can be tracked to have a relative value based on known market prices and....oh whats the term for content of precious metals in coins...it's not karats... but yeah, that. Overall, its best to but Avery and Levasseur at the top, but to call a "winner", well, that's gonna result in some debate that still isn't fully settled yet.

I say in the end Drake got the biggest capture, but couldn't walk away with it all.

First of all, I'd possibly agree with others that Francis Drake should be mentioned, for his capture of the Cacafuego rather than the mule trains. The issue of whether he was a pirate or a privateer is a highly nuanced one and depends on whether the question is approached from a technical, legal, or moral standpoint. However, since the OP specified 17th or 18th century, and Drake was active in the 16th, I think it's best to avoid that sticky quagmire altogether.

I also think that we can probably dispense with Bellamy. He did well, but wasn't in the same league as the 'top' pirates. To answer the question, we need to look at Henry Every and Richard Taylor.

There were various estimates of the size of Henry Every's total haul, ranging from about £100,000 to about £600,000. The most precise estimate was given by Philip Middleton, who said each man had a share of £970, and there were 170 men (14 Danes, 52 French, 104 English). This would give a total of £164,900. Every himself received a double share, and other officers received extra part shares, so the figure should be rounded up slightly - perhaps £170,000.

However, William Philips, who was less precise than Middleton but probably just as reliable (if not more so) said 'there were about 160 shares at £700 a piece or thereabouts, but it was not very equally devided.' In total Philips claimed that the Gang-i-Sawai was carrying £150,000, but he may been referring to cash only.

To confuse matters, at the trial of five of Every's men, John Dann testified that 'some had £1,000, some £500, other £3,000.' If we assume that Every's double share was the £3,000 that Dan mentioned, and the average share was £1,500, and that the number of shares rather than the number of men was an arbitrary 175, that would give a total of £262,500.

So, between Middleton's figure of £164,900 and Dan's £262,500 there's a fairly wide gap, but nothing like the £600,000 estimated by the Indians. The East India company were prepared to accept a figure of £325,000, but that must have included the value of spoil taken from the Fateh Mohammed, and possibly some rounding up in compensation for damage and insult. The figure has to be taken as approximate anyway because so much of the value was in precious stones and other commodity whose price would depend on a number of factors, plus small sums given away to the crews of other ships and as bribes, but a round figure of about £250,000 for the Gang-i-Sawai seems reasonable.

The Nuestra Senora de la Cabo is a different matter. There is some debate as to who was actually present at her capture. Richard Taylor was definitely present and in command of the Victory. Richard Moor, a surgeon forced into the pirates' service said that the Cassandra was commanded by Jasper Seagar. After capturing the Cabo, Moor said the pirates made their way to St. Mary's, Madagascar, 'and there the sd Seager dyed and ye aforesaid le Boos [La buse/Levasseur] was made Captain of the Cassandra in his room.'

The confusion arises because the French governor of Martinique, the Count of Ericeira, claimed that La Buse was in command. Given the confusion of the evidence, what seem likely is that Moor was correct (and was certainly in a better place to know) and the Taylor and Seagar commanded the two pirate ships, and La Buse was sent to negotiate with the French authorities who naturally assumed that he was in command.

None of which matters as to how much the prize was worth. Richard Lazenby, a captive on Taylor's ship, was told that the diamonds alone were worth '3 or 4 million dollars', which at an exchange rate of 4s 6d to the dollar gives a figure of between £681,818 and £909,090, for the diamonds alone. Other estimates are lower, but a round figure of £1,000,000 in total should be approximately correct.

That, of course, is substantially greater than the value of the Gang-i-Sawai, so if you want to know the single richest prize, there it is.

But there's another factor that needs to be taken into account, and that is the relative number of men sharing the prize. Taylor's company, across both ships, was estimated at 480 at the minimum, and could have been well over 500, giving an individual share of around £2,000 per man. Every's cruise may have netted them as much as £325,000 (by the East India Co. estimate), and been divided by possibly as few as 160 men, which would make each man's share also around £2,000. In fact, Taylor's men probably did slightly better than Every's, but perhaps not by a great deal.

Paging /u/eternalkerri and /u/davidaop for this one.

To clarify, your subject line asks about a "single prize" but the body of the question seems to be asking about a "haul" -- do you mean a single ship, or the proceeds from an entire cruise?

If pirates from earlier eras interest you, Francis Drake returned plunder worth a declared £307,000 (the real total was probably more than £600,000 but his crew heavily plundered his haul) from his circumnavigation in 1577-78. He captured the Nuestra Señora de la Conception laden with 26 tons of silver (and numerous other trade goods) on the voyage.