I think both are important and correct.

1) Don't try to beat the market (in the long run).

2) Don't try to time the market (in the long run).

hehe.

interesting. I am trying to do both

1) Beat the market (20 year time frame)

2) time the market (20 year time frame).

Your entry point is critical. exiting strategy should be set before you buy anything.

if during the 20 year time frame, say 4 year bear, 3 year bull, (roughly). if this 20 year started with a bear,

4 + 3 + 4 + 3 + 4 + 2 (2.67 bull, 3 whole bear market)

if starts with a bull, 3 + 4 + 3 + 4 + 3 + 3 (3 whole bull, 2.75 bear)

say in bull market, return is 50%, bear return is -20%

if you have 10k, at the end of the 20 year, you have:

if you have 10k, at the end of the 20 year, you have:

if start with bear market, if you don't time the market, you will end up with

10 (0.8)^3 (1.5)^2 (1.5 * 2/3) = 11.52k

if start with bull market, if you don't time the market, you will end up with

10 (1.5) ^3 (0.8)^2 (0.8 * 3/4) = 12.96k

if you time the market, but timing is not perfect, (nobody can), so you get 40% return on the bull market, and you avoid loss on the bear market.
for the first case, you got 2.67 bull
10K (1.4)^2.67 = 24.55k

for the second case, you get 3 whole bull
10k (1.4)^3 = 27.44k

so now you can tell the difference.

for individual invester, we do not have 50 years. If you have been through the last dot come crash, and lost 80% of the money, you may never get the chance to come back.

Legitimate scam, that's what many market ananysis or MF manager want you to believe, so-called invest in long term. for many of us here, we are young, we dont have too much money. we have enough time to start from 0, but for many others, this is not the case.

Why do I say 20 year time frame, most of us will not start serious investing until early 30, this is when you have a stable job, and start to make significant more than you spend. say you invest till some time in early or late 50s, you've got roughly 20-25 years.

I can roughly understand your calculation.  However!!!  How can you tell if the next 3-4 yrs are going to be bull/bear market?  You calculation is based on a given assumption that YOU KNOW that market is going to be bull/bear market.  There are actually three market:  Bull, Bear and Flat.  Probaility-speaking, each market will have equal chance of occuring in any given year(that is 33.333333% chance for each market occurance).  You have to take the weighted average of all your projected numbers, which means that your number will be significantly diluted.  Plus, more importantly, I think it is very important to define my defination of "market".  Market mean the whole market that contains all possible asset class (equity, bonds, real-estate, commodity, and many others).  So, a bull market in equity can translate into bear market in other asset class.  I believe that your calculation seems to be only restricted in equity market (correct me if I am wrong).  When you consider the whole-market concept, the expected return of a well-diversifed portfilio should be the weighed average return of all its asset class.  Bottom line:  (1)I don't know how to apply calcuations base on "Certain Future Events" (I"know" next yr will be bull/bear market), (2) Market concept is based on a whole-market concept.  I can you that you must have taken lot of time-value class.