KNITTING ARMHOLES AND SET-IN SLEEVES ACCORDING TO M. V. MAXIMOVA.

The desire to write this entry arose after questions - how do I knit the sleeve, and why does it fit so well?
I have been knitting for a long time, since I was 12, and my main teacher was M. V. Maksimova's book "Knitting ABC". It is this book that taught me how to properly knit armholes and sleeve caps. Of course, each item requires some adjustments, but the basic calculations always remain unchanged.
If you take this method as a basis, you will soon have neat set-in sleeves. 
I wish everyone good luck! 
Calculation and knitting of the sleeve cap. 

For the calculation and knitting of the sleeve cap, it is most expedient to use a technique developed through practice. Regardless of the yarn and needle size you use, this technique gives fairly accurate results. Depending on the knitting density, only the number of calculation digits changes: the looser the fabric, the fewer digits there are. 

Let's familiarize ourselves with this calculation. Divide the number of stitches in segment AB (fig. 174) into 3 equal parts (54 st. : 3 = 18 st.). If there is a remainder, add it to the 1st part. Then divide the stitches of each part into groups. 

Fig. 174 Calculation for knitting the sleeve cap 

Divide the stitches of the 1st part into triples and doubles, with the first half into triples and the second half into doubles (3 + 3 + 3 + 2 + 2 + 2 + 2 = 17), add the remainder to the first number (3 + 1 = 4). 

Divide the stitches of the 2nd part into units (18 units); the stitches of the 3rd part - into triples (3 + 3 + 3 + 3 + 3 + 3 = 18). If there is a remainder, add it to the first number, counting from the highest point of the cap (point O). 

Transfer the calculation results to the pattern. 

Now you can start knitting the sleeve cap. 

At the beginning of the right side row of the 1st part (point B), secure 4 stitches in a row and knit the row to the end. Turn the knitting and at the beginning of the wrong side row, secure another 4 stitches. Then continue to close stitches according to the calculation at the beginning of each row (either right side or wrong side), until you have decreased 18 stitches on both sides of the sleeve. 

For the first third of the stitches of the 2nd part (18 st. : 3 = 6 st.), decrease 1 stitch at the beginning and end of each right side row. For the second third (6 stitches), decrease in the same way, but not in every right side row, only every other one. For the last third (6 stitches), decrease just like the first one. 

Secure the stitches of the 3rd part according to the calculation in the exact same way as in the 1st part: either at the beginning of the right side or at the beginning of the wrong side row. When there are 6 stitches left on the needle (3 stitches from the right side of the cap plus 3 stitches from the left), close them in a row. 

When knitting set-in narrow sleeves, there is a certain pattern that is worth considering. It has been observed: if the arm length measurement is 52-60 cm (with normal fullness of the arms), then increases on the sleeve should be made every 6th row. If the length measurement is 48-51 cm (short arms) with the same arm fullness, then a different rhythm of increases is necessary - once every 6th row, once every 4th. For full and short arms (48-51 cm), stitches on the sleeve need to be increased every 4th row. Knowing this, you can skip the calculation of increases on the pattern and knit the sleeves taking into account these practical conclusions.
Photo from the internet.