The Thunderbird position number (i.e. 1,2,3,..) are not specific to one USAF
serial number. These decals are taken off and put on based upon the operational dynamics. It is not uncommon to have them taken off at night and put on another sometimes in the morning before a show. This is because an aircraft might be taken down for tech reasons at the last minute. So you best bet is to ask the Thunderbirds which aircraft is flying in which slot on one particular day. I have talked to TBird maintainers before and they have updated me on a day to day basis. However, I can tell you that sometimes, there have been changes after they gave me the update. Remember that there is usually two reserve aircraft at a show.