Just checked the accuracy of my SuperOcean from 1996 and was quite surprised to note that it is within 1 second over 24hrs. This got me to thinking, has Breitling done anything different to its movements since 2000? I do understand that the COSC process is likely more vigorous than what my average day puts this SO through, but nice to know that with my use the watch is very accurate. Is the 17 movement in my SO exactly the same now as it was in 1996? I guess I'm curious to know if Breitling made any changes to quality control or parts/precision of its watches with the move to send all its watches to COSC starting in 2000. I'm not familiar enough with Breitlings to know which models were and were not certified pre-2000. Was it only the higher-end models? Did they make the lower end of the product line more precise to allow them to send all their watches for COSC? I'm pretty much down the middle of the road when it comes to the value or meaning of COSC, but more interested in questions like those above.

Breitling claimed that their movements were made to Chronometer standards prior to the the range-wide COSC certification, but never indicated if they changed anything after they started submitting all movements to COSC.

Very few watches were submitted to the COSC prior to the change, it was usually reserved only fir solid gold Chronomats and similar types of special higher end models.

You probably know that Breitling don't manufacture their own movements - they buy from suppliers, essentially in kit form and then assemble, making some modifications along the way.

The kits (technically 'ebauches') are available in different grades, and Breitling has always bought the highest grade which is the version designed to be COSC certified (though not certified at time of purchase).

There are always tweaks made by the movement manufacturer and br Breitling so there will be minor differences, but many movements date from the 60s and 70s with ony minor variations so essentially yes, they are the same movement.

Right, I'm aware that most are slightly modified ETA or Valjoux movements. Have there been any improvements in the friction-bearing parts of the movement that improve long-term accuracy and reliabilty?