Top Eleven Tactics for the 4-3-3 Narrow formation

Summary

The 4-3-3 Narrow formation is the best formation to attack through the middle in Top Eleven.

Supportive team mentality

Defensive, Normal, Attacking, Hard Attacking

Unsupportive team mentality

Hard Defending

Advantages of the 4-3-3 Narrow formation in Top Eleven 

• It is high scoring formation.
• You have very few type of positions so it is easy to manage substitutions during the match.
• With three Strikers (ST) up front, there will always be attacking options for the team to exploit. Coupled with the fullbacks and midfielders pushing forward, this makes for a potent attacking force.
• With three center midfielders you can control the center of the pitch and force your opponent to play out wide.
• The focus passing styles "Through The Middle" works amazingly. 
• This formation is capable of all three available passing styles, Short, Mixed, and Long.
• The offside trap works really well with this formation.

Disadvantages of the 4-3-3 Narrow formation in Top Eleven

• You have only option to choose focus passing style "Through The Middle" and there is no threat on the wings for opposition.
• Your right and left defenders (DR & DL) need more than 120% fitness and speed attributes because they tire out more.
• Opposition can take advantage of the space on the wings. And if opposition is playing with strong attacking right and left midfielders, be ready to concede the goals.
• You need very strong center defenders with special abilities.
• Sometimes, this formation leaves space for opposition for counterattacks so you need a Goalkeeper (GK) with at least 130% overall quality and 140% Rushing Out attribute.
• The Man-To-Man marking style isn't sufficient against strong opponents.

Recommended special abilities

• Your center defenders should have the special abilities of Defensive Wall and Aerial Defender.
• One of your strikers (ST) should have the special ability of a One-on-one scorer. It can be very helpful to score during the counterattacks.
• For more creativity in the midfield, one of your center midfielders (MC) should have the special ability of Playmaker.
• One of your center midfielders (MC) should have the special ability of Dribbler.

Recommended extra roles

• All of your center midfielders (MC) should have an extra role of defensive center midfielder (DMC). It supports your defense a lot.
• Your both side defenders (DR & DL) should have extra roles of right and left midfielders (MR & ML). It helps to cover the side space on the pitch. They should be trained for third role for center defender (DC). Though it is not necessary but it can be very helpful to keep balance in the defense line.

Attacking tactics for the 4-3-3 Narrow formation

Team mentality, Attacking, Focus passing, Through The Middle, Passing style, Mixed, Force counter-attacks, Off
Pressing style, High, Tackling style, Hard, Marking style, Zonal, Play offside trap, On

Normal tactics for the 4-3-3 Narrow formation

Team mentality, Normal, Focus passing, Through The Middle, Passing style, Mixed, Force counter-attacks, On
Pressing style, High, Tackling style, Hard, Marking style, Zonal, Play offside trap, Off

Defensive tactics for the 4-3-3 Narrow formation

Team mentality, Defensive, Focus passing, Through The Middle, Passing style, Mixed, Force counter-attacks, On
Pressing style, High, Tackling style, Hard, Marking style, Zonal, Play offside trap, Off

Final note

Even if you follow all these instructions, I guarantee an 80% of good result. Your team's training bonuses, morale, health condition, injuries during the match, weather conditions, and referee's decisions may change the outcome of the match.