Hello,
It depends on how the harddisk firmware treats the bad sectors.
In the block from the wiki I posted, you can read about it.
Here is a copy of that text again:
Count of "unstable" sectors (waiting to be remapped, because of unrecoverable read errors).
If an unstable sector is subsequently read successfully, the sector is remapped and this value is decreased.
Read errors on a sector will not remap the sector immediately (since the correct value cannot be read and so the value to remap is not known, and also it might become readable later); instead, the drive firmware remembers that the sector needs to be remapped, and will remap it the next time it's written.
[58]
https://kb.acronis.com/content/9133
However, some drives will not immediately remap such sectors when written; instead the drive will first attempt to write to the problem sector and if the write operation is successful then the sector will be marked good (in this case, the "Reallocation Event Count" (0xC4) will not be increased).
This is a serious shortcoming, for if such a drive contains marginal sectors that consistently fail only after some time has passed following a successful write operation, then the drive will never remap these problem sectors.
From the acronis lik:
Recommendations
This is a critical parameter. Degradation of this parameter may indicate imminent drive failure. Urgent data backup and hardware replacement is recommended.
Bertus