Hopefully you all know by now that autocancelled aerials are when you perform an aerial and time your landing in order to eliminate lag. This is usually done by performing the aerial soon after jumping so that it has completed by the time you land. An example of this is Lucas's short hopped Nair where you simply press A after jumping and don't fast fall.
Lag cancelling Lucas's Bair presents a problem for this though. A regular short hopped Bair will not autocancel with Lucas leaving you with some lag upon leaving (although it is relatively little.)
Fortunately for us, there is another way to autocancel some aerials. You may notice that if you do an aerial just as you're about to touch ground the move cancels completely immediately putting the character into his neutral standing position. Normally this is useless because there isn't time for the hitbox to come out. However, with proper timing you can get part of the hitbox of Bair out while autocancelling this way.
The way to effectively do this is to simply short hop fast fall your Bair. Initiate your back aerial as you are approaching the ground NOT on the way up. Initially you will probably do it too late and Lucas will do a little flip but no sparks will come out. However if you adjust your timing slightly you should be able to get a single spark out and still have the move autocancel.
If you are autocancelling the move correctly you should be able to jab or do any other move directly out of it. It should be very fast. Compare it to regular short hopped Bair without fast falling and you should see a noticable difference.
Application
Here's the fun part. This is almost entirely a defensive maneuver but it can have some impressive gains for you if you use it right. The basic application of this is to create a wall between you and your opponent while at the same time retreating to a safer area to hit with PK Fires. The single spark will provide an adequate wall between you and the opponent which protects you from above and from the side. Proper spacing is essential!! I find it's far easier to put this to good use with the C-stick set to smashes so that you can more easily control your movement during Bairs.
Your aim while using this move should be to hit with the sourspot of Bair. The sourspot is the point in the move which does the least damage and has the least knockback. This should be the very edge of the spark furthest away from you. Hitting with the sourspot will cause your opponent to be knocked back a very short distance in most cases. Because you've autocancelled your Bair, you should then have a free shot with a forward tilt or possibly another Bair. Hitting with the sourspot also has a chance of making the opponent trip which means you get a free forward smash. If you don't hit with the sourspot they will be hit too far away for you to hit them again.
Should your opponent decide to jump toward you in an attempt to do an aerial, a Bair will almost always spike them straight downward. Due to the speed that Bair knocks opponents this will be pretty difficult for them to tech. From this point you should be able to hit them with a forward smash or possibly Lucas's jab lock as long as you autocancelled the Bair. Even if they do tech it they should be out of your face for the moment and you can proceed to hit them with PK Fires or else try for a techchase.
Why not use a Nair instead?
Priority and range. Bair has significantly higher priority than Nair which will help you escape from getting badly punished. This is not to say that you shouldn't use Nairs defensively on occasion but in lots of cases autocancelled bairs are better. A lot depends on the opponent character. Bair's range also makes it much easier to space.
Lag cancelling Lucas's Bair presents a problem for this though. A regular short hopped Bair will not autocancel with Lucas leaving you with some lag upon leaving (although it is relatively little.)
Fortunately for us, there is another way to autocancel some aerials. You may notice that if you do an aerial just as you're about to touch ground the move cancels completely immediately putting the character into his neutral standing position. Normally this is useless because there isn't time for the hitbox to come out. However, with proper timing you can get part of the hitbox of Bair out while autocancelling this way.
The way to effectively do this is to simply short hop fast fall your Bair. Initiate your back aerial as you are approaching the ground NOT on the way up. Initially you will probably do it too late and Lucas will do a little flip but no sparks will come out. However if you adjust your timing slightly you should be able to get a single spark out and still have the move autocancel.
If you are autocancelling the move correctly you should be able to jab or do any other move directly out of it. It should be very fast. Compare it to regular short hopped Bair without fast falling and you should see a noticable difference.
Application
Here's the fun part. This is almost entirely a defensive maneuver but it can have some impressive gains for you if you use it right. The basic application of this is to create a wall between you and your opponent while at the same time retreating to a safer area to hit with PK Fires. The single spark will provide an adequate wall between you and the opponent which protects you from above and from the side. Proper spacing is essential!! I find it's far easier to put this to good use with the C-stick set to smashes so that you can more easily control your movement during Bairs.
Your aim while using this move should be to hit with the sourspot of Bair. The sourspot is the point in the move which does the least damage and has the least knockback. This should be the very edge of the spark furthest away from you. Hitting with the sourspot will cause your opponent to be knocked back a very short distance in most cases. Because you've autocancelled your Bair, you should then have a free shot with a forward tilt or possibly another Bair. Hitting with the sourspot also has a chance of making the opponent trip which means you get a free forward smash. If you don't hit with the sourspot they will be hit too far away for you to hit them again.
Should your opponent decide to jump toward you in an attempt to do an aerial, a Bair will almost always spike them straight downward. Due to the speed that Bair knocks opponents this will be pretty difficult for them to tech. From this point you should be able to hit them with a forward smash or possibly Lucas's jab lock as long as you autocancelled the Bair. Even if they do tech it they should be out of your face for the moment and you can proceed to hit them with PK Fires or else try for a techchase.
Why not use a Nair instead?
Priority and range. Bair has significantly higher priority than Nair which will help you escape from getting badly punished. This is not to say that you shouldn't use Nairs defensively on occasion but in lots of cases autocancelled bairs are better. A lot depends on the opponent character. Bair's range also makes it much easier to space.