user15511: I was a hardcore 1.c4 player. But, for quite some time, the popularity of Nakhmanson Gambit, Jerome Gambit etc. has encouraged me to experiment with 1.e4.
I have read 1.e4 with backup plan before. Now I am preparing myself to master the entire 1.e4 repository [ECO B00 - C99] for white, as well as for black. Since I am completely beginner in this line, I have the following questions:
How can I understand, which opening seeks more attention than others? Should I follow the database to find the most popular reply or it's better to stick with the ECO code serially? How can I link the connection between two openings? (eg., Scotch Gambit and Urusov Gambit)

user14202: Adopting e4 is a huge undertaking.  Since you played the English, I recommend you incorporate the King's Indian Attack into your repertoire as you can play it against anything you haven't studied yet.
A gambit repertoire is not a bad idea either. You might be able to link lines like:
1.e4 d5 2.d4 dxe4 3.Nc3
1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.f3
1.e4 c5 you can play 2.c4 and head for some kind of English or The Smith-morra gambit, and  Grand Prix Attack are good alternatives.  Otherwise, Main line Sicilians would take a couple years to learn.
There are plenty of e4 repertoire books/videos, and they try to link lines/simplify things.

user924: The special feature of a 1.e4 repertoire is that transpositions are rare. You can have independent repertoires against each of black's replies. This is very different from 1.c4, 1.d4 and 1.Nf3 where moves can often be played in many different orders and you always have to watch out for transpositions between your various lines.
Then these are the "big four":
1...e5 -- The Open Game
1...c5 -- The Sicilian
1...e6 -- The French
1...c6 -- The Caro-Kann
Most of your time should go to those, especially the first three (the CK is also very good but not as popular at amateur level).
Then there is the rest, like
1...d5 -- the Scandinavian
1...d6 and 1...g6 -- the Pirc and Modern (there are transpositions between those)
1...Nf6 -- the Alekhine
And other lines that you can skip for now.
The reason for this is that 1.e4 puts an undefended pawn in the center, and the intended follow-up 2.d4 is hard to prevent as it will be defended by the queen. This is different from 1.d4 where 2.e4 is easy to prevent. That means all replies must immediately have some specific way to deal with that, and the different ways of doing that immediately prevent transpositions.
1...e5 -- black just does the same. 1...c5 -- black will exchange his c-pawn for the d-pawn if it arrives on d4. 1...e6 and 1...c6 -- black will also put a pawn on d5. 1...d5 black immediately puts a pawn on d5 but can't recapture with a pawn. 1...Nf6 -- black attacks the undefended e4 pawn. 1...d6 and 1...g6 -- black lets white play 2.d4 and intends to attack the center later.
Hope this helps.

15511: <p>I was a hardcore 1.c4 player. But, for quite some time, the popularity of Nakhmanson Gambit, Jerome Gambit etc. has encouraged me to experiment with 1.e4.</p>
<p>I have read <a href="https://chess.stackexchange.com/questions/16349/1-e4-with-backup-plan">1.e4 with backup plan</a> before. Now I am preparing myself to master the entire 1.e4 repository [ECO B00 - C99] for white, as well as for black. Since I am completely beginner in this line, I have the following questions:</p>
<p><strong>How can I understand, which opening seeks more attention than others? Should I follow the database to find the most popular reply or it's better to stick with the ECO code serially? How can I link the connection between two openings?</strong> (eg., Scotch Gambit and Urusov Gambit)</p>
 14202: <p>Adopting e4 is a huge undertaking.  Since you played the English, I recommend you incorporate the King's Indian Attack into your repertoire as you can play it against anything you haven't studied yet.</p>
<p>A gambit repertoire is not a bad idea either. You might be able to link lines like:
1.e4 d5 2.d4 dxe4 3.Nc3
1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.f3</p>
<p>1.e4 c5 you can play 2.c4 and head for some kind of English or The Smith-morra gambit, and  Grand Prix Attack are good alternatives.  Otherwise, Main line Sicilians would take a couple years to learn.</p>
<p>There are plenty of e4 repertoire books/videos, and they try to link lines/simplify things.</p>
 924: <p><em>The</em> special feature of a 1.e4 repertoire is that transpositions are rare. You can have independent repertoires against each of black's replies. This is very different from 1.c4, 1.d4 and 1.Nf3 where moves can often be played in many different orders and you always have to watch out for transpositions between your various lines.</p>
<p>Then these are the &quot;big four&quot;:</p>
<p>1...e5 -- The Open Game</p>
<p>1...c5 -- The Sicilian</p>
<p>1...e6 -- The French</p>
<p>1...c6 -- The Caro-Kann</p>
<p>Most of your time should go to those, especially the first three (the CK is also very good but not as popular at amateur level).</p>
<p>Then there is the rest, like</p>
<p>1...d5 -- the Scandinavian</p>
<p>1...d6 and 1...g6 -- the Pirc and Modern (there are transpositions between those)</p>
<p>1...Nf6 -- the Alekhine</p>
<p>And other lines that you can skip for now.</p>
<p>The reason for this is that 1.e4 puts an undefended pawn in the center, and the intended follow-up 2.d4 is hard to prevent as it will be defended by the queen. This is different from 1.d4 where 2.e4 is easy to prevent. That means all replies must immediately have some specific way to deal with that, and the different ways of doing that immediately prevent transpositions.</p>
<p>1...e5 -- black just does the same. 1...c5 -- black will exchange his c-pawn for the d-pawn if it arrives on d4. 1...e6 and 1...c6 -- black will also put a pawn on d5. 1...d5 black immediately puts a pawn on d5 but can't recapture with a pawn. 1...Nf6 -- black attacks the undefended e4 pawn. 1...d6 and 1...g6 -- black lets white play 2.d4 and intends to attack the center later.</p>
<p>Hope this helps.</p>
