Nobody has found a trick for fast mining, that's just good luck. Sometimes it can be an hour or two between blocks, other times it can just be seconds between them.

Remember, mining has changed. ITs more centralized.. Did one person or one machine find those four blocks. i guess its hard to say anymore.. people that mine usually have tens or hundred of terabytes of power.. Soon, you will need hundreds of petahashes to find a block, lol... I have mixed feelings when bitcoin price took off. It made me a tidy sum, yet it made it so mining wasn't profitable for me. So, i think I probably lost money. it brought rich people out of the wood work to mine that would have never mined had bitcoin stayed at the 10 to 15 dollar level. too many cooks in the kitchen... When I was doing the math to figure out if spending 30k on a mining rig was worth it back in the day, the most I thought bitcoin could go up in the 4 years that i did the math was about 50 dollars a coin and I thought it would stay sub 20 dolllars for years. so, I was way off, lol..

First of all those 4 are not found by the same address, second look at the places where they supposed to be found.
This happens ofcourse not often but it happens that some people get shortly after another some blocks.
They seldom fall at the same spot but as you can see 2 are at the same spot and the 2 earlier ones elsewhere.
So for as i can see does it look so special

There is nothing odd going on here.  There is no "pre-mine" or some "trick for fast mining".  It is like seeing a dog in the clouds.  There isn't really a dog here.

Which happens to be just under 750 metric kilobytes, which is the default maximum block size.

Not close at all. A difference of 300,000,000 is about one thirteenth of the maximum range, which means consecutive nonces will be this close together over 10 times a day.

(Edited to correct drunken math)

10 minutes, actually.

I kind of doubt it...

4Byte nounce is between 1 and 2^32-1=4.294.967.295 right? Where is your 300.000 being 1/13th coming from?

I thought I posted by the times indicated by blockchain.info at the time. Note that timestamps are malleable and timestamps of reception by blockchain.info don't seem to be accurate. Block timestamp and blockchain.info timestamp for reception are not in chronological order for blocks 354642 and 354643 (this is not strange and happens quite often). Malleability of blocks timestamps may explain this fact but not timestamp of reception by blockchain.info (that may just copy the block timestamp).

I meant 300,000,000 (that's the closeness we're talking about right?), but I misplaced a few zeros somewhere around the second glass of absinthe. This is why you shouldn't drink and derive.

They are. The timestamps are exactly the same, down to very second.

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Nonce are not uniformly distributed because miners always start scanning from 0. Therefore, small nonce is more likely to be found on the blockchain.

https://bt.irlbtc.com/view/985846.0