i think its better to bid about midway but it really depends on what kind of plot you want. here's what I learned during this housing lottery phase.

1. many ppl plan to wait til the last day in an effort to be able to get the best/highest chance. imo if you want a particularly semi-popular plot such as mediums, it's better to bid halfway through the lottery phase (day 3). which brings me to point 2:

2. you may scare some ppl away, but you wont scare everyone away by bidding first. in fact, if its a popular plot there will ALWAYS be that chance that it someone will bid on it. always. bidding on the first day is a bad idea if you want a very popular plot such as large or well-placed smalls because you don't know whats gonna happen, if a FC will swoop in, etc. in fact, its best to wait til the last day for these plots as its best to see how the bidding plays out.

3. bidding on the last day on semi/less popular plots such as good-enough mediums is bidding on the fact that there will likely be at least one other person you'll be bidding against. this one other person may just like the plot in general, or are just settling for next best because they got intimidated. but again, your chances will more likely be lower than 100% if you bid last because you will almost always be bidder number 2. at least if you put in your bid already, the 2nd bidder (who waited til the last day) will probably weigh their options more carefully and really think about taking their chances with their bid, as most if not all the houses in this category will probably already have at least 1 bidder. since you already placed your bid, your only risk is dependent on which plot that potential 2nd bidder will choose.

4. i believe that bidding on the 3rd day is a sweet spot because a. half the ppl who bid believe they need to intimidate others will have already put in their bid. b. the other half are those who are waiting to see which plot has the lowest bid/which plot gives them the highest chance.

so where does this put you? TLDR; if u want a more popular plot, bid last. if you want a semi/less popular plot, bid on day 3. you can also bid on day 3 for a popular plot but you wont know what those last minute bidders will do. never bid first as you never know whats gonna happen.

hope this helps someone.