Looking on the internet deeply has found these results:

at the middle of is the most popular phrase on the web.

in the middle of 1295,000,000 results on the web	at the middle of 1360,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I'm in the middle of a serious online debate about objectivist philosophy. He's in the middle of an attack. I can't be in the middle of that war. She's in the middle of a huge case. You're in the middle of a seizure. I'm never in the middle of anything. Now I'm stuck in the middle of all this. You're in the middle of a big sandwich.	The QuickMask is now disabled. The selection occupies the right half part of the image (marching ants) because the limit of the selection is at the middle of the gradient. Each of them ate as fast as they could, edging their chair forward, and they met at the middle of the trencher. 1 + = sample containing 1 % of cows' milk and spiked with pure bovine casein at the middle of the track. There is, therefore, good reason to conclude that slightly soluble compounds (at the middle of this range) have similar carcinogenic properties. All I need you to do... is just aim at the middle of the debris. And at the middle of this Levellers' paradise, Angelica Fanshawe, now Countess of Seacourt. CM = percentage of cows' milk; 1 + = sample containing 1 % of cows' milk and spiked with pure bovine casein at the middle of the track. Look at the middle of Discovery.

in the middle of

1295,000,000 results on the web

at the middle of

1360,000,000 results on the web

More popular!

The QuickMask is now disabled. The selection occupies the right half part of the image (marching ants) because the limit of the selection is at the middle of the gradient.
Each of them ate as fast as they could, edging their chair forward, and they met at the middle of the trencher.
1 + = sample containing 1 % of cows' milk and spiked with pure bovine casein at the middle of the track.
There is, therefore, good reason to conclude that slightly soluble compounds (at the middle of this range) have similar carcinogenic properties.
All I need you to do... is just aim at the middle of the debris.
And at the middle of this Levellers' paradise, Angelica Fanshawe, now Countess of Seacourt.
CM = percentage of cows' milk; 1 + = sample containing 1 % of cows' milk and spiked with pure bovine casein at the middle of the track.
Look at the middle of Discovery.