An equal number of additional write operations compensates for {TAIL ~ the additional reads} at {HEAD ~ a later point} 
An equal number of additional write operations compensates for { TAIL ~ the additional reads } at { HEAD ~ a later point }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD