To merge-mine or not to merge-mine

[crazyideas21]

I'm a researcher on crypto-currencies. Lately, when I was examining the blockchain of Dogecoin, I found that a small number of blocks were not merged-mined, even though Dogecoin had already switched to merge-mining.

Here's one example: https://www.zpool.ca/explorer/DOGE?start=972420

You can see that Blocks #972415 and #972403 were not merge-mined (PoW). All other blocks were merge-mined (AuxPoW). This happened in November 2015, more than a year after Dogecoin had switched to merge-mining.

I would expect all blocks to be merge-mined at this point, since a miner would be generating dogecoins for free while mining another Scrypt coin like Litecoin. In other words, it seemed irrational to be mining just Dogecoin, given that you could also have mined Litecoin.

So how would you explain my observation? Were a small number of miners behaving irrationally?

[philipma1957]

I'm a researcher on crypto-currencies. Lately, when I was examining the blockchain of Dogecoin, I found that a small number of blocks were not merged-mined, even though Dogecoin had already switched to merge-mining.

Here's one example: https://www.zpool.ca/explorer/DOGE?start=972420

You can see that Blocks #972415 and #972403 were not merge-mined (PoW). All other blocks were merge-mined (AuxPoW). This happened in November 2015, more than a year after Dogecoin had switched to merge-mining.

I would expect all blocks to be merge-mined at this point, since a miner would be generating dogecoins for free while mining another Scrypt coin like Litecoin. In other words, it seemed irrational to be mining just Dogecoin, given that you could also have mined Litecoin.

So how would you explain my observation? Were a small number of miners behaving irrationally?

Or some one did the wrong setup and fixed it once they,saw the,mistake.

The blocks are very close to one another.